Hydraulic Brake System Cadillac Escalade GMT900

Fastener Tightening Specifications

Brake Component Specifications

Brake System Specifications

Scheme 1

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit/System Description

The brake fluid level switch monitors the level of brake fluid in the master cylinder. When the instrument panel cluster (IPC) sees the brake fluid level switch input closed, it turns ON the Red Brake Warning indicator and sends a serial data message to the electronic brake control module (EBCM) that the brake fluid level is low.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

1. Low brake fluid is detected.
2. A short to ground exists on the signal circuit.

Action Taken When the DTC Sets

1. The EBCM disables the antilock brake system (ABS)/traction control system (TCS) dynamic rear proportion (DRP) and vehicle stability enhancement system (VSES).
2. A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

1. The condition for the DTC is no longer present.
2. The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Reference Information

Schematic Reference

Hydraulic Brake Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Brake Warning System Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Inspect for proper brake fluid level, the fluid level should be at or above the proper level. If low, refer to «Brake Fluid Loss»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-fluid-loss) .
2. Ignition ON, observe the scan tool IPC Brake Fluid parameter. The reading should be OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the brake fluid level switch.
2. Test for less than 10 ohm between the ground circuit terminal A and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool IPC Brake Fluid parameter is Ok. If not the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the IPC.
4. Install a 3A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool IPC Brake Fluid parameter is Low. If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the IPC.
5. If all circuits test normal, test or replace the brake fluid level switch.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Brake Fluid Level Indicator Switch Replacement (Two-mode Hybrid)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Brake Fluid Level Indicator Switch Replacement (JD9, JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for IPC replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The electronic brake control module (EBCM) provides power and ground circuits to the power brake booster actuator. The power brake booster actuator converts electrical inputs into a mechanical force to apply the brake booster to assist the driver as necessary in stability control. The EBCM monitors the vacuum level in the power brake booster, and will set a DTC if the vacuum is too low.

C0299 00

1. Ignition ON.
2. Ignition voltage is greater than10 volts.

C0299 5A

1. Ignition ON.
2. Engine Running.
3. Ignition voltage is greater than 10 volts.

C0299 00

The EBCM detects a short to ground, open/high resistance or a short to voltage on the power brake booster actuator control circuits.

C0299 5A

1. No vacuum is detected in the power brake booster for approximately 10 seconds after start-up.
2. Low vacuum is detected in the power brake booster for approximately 60 seconds or longer after start-up, or is detected while driving.

1. The EBCM disables the active vacuum booster for the duration of the ignition cycle.
2. A DIC message and/or a warning indicator may be displayed.

1. The condition for the DTC is no longer present.
2. The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Schematic Reference

Hydraulic Brake Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Brake Assist System Description and Operation (Vacuum Assist) or Brake Assist System Description and Operation (Hydraulic Assist)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, disconnect the harness connector from the power brake booster actuator.
2. Test for less than 25k ohms of resistance between the harness connector terminal 5 and ground. If greater than 25k ohms, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the actuator harness connector terminal 1 and terminal 5.
4. Ignition ON, command the Active Brake Booster to ON and OFF with a scan tool. If the test lamp remains OFF during the commands, test for a short to ground or an open/high resistance on either control circuit. If the circuits test normal, replace the electronic brake control module EBCM. If the test lamp is always ON, test the control circuits for a short to battery positive. If the circuit tests normal, locate and repair the source of the vacuum leak.
5. If all circuits test normal, test or replace the vacuum brake booster assembly.
6. If all circuits test normal, and no vacuum leaks were found, replace the electronic brake control module (EBCM).

Verify DTC C0299 5A is not set.

1. If the DTC is set, repair the source of the vacuum leak. Refer to «Brake Assist System Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-assist-system-diagnosis) .

Component Testing

C0299 00

1. Ignition OFF, disconnect the harness connector at the power brake booster actuator.
2. Test for infinite ohms of resistance between the actuator terminal 1 and ground. If less than infinite ohms, replace the vacuum brake booster assembly.
3. Test for 2-3 ohms of resistance between terminals 1 and 5 at the power brake booster actuator.

1. If the test is infinite resistance, replace the vacuum brake booster assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Power Vacuum Brake Booster Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for EBCM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The electronic brake control module (EBCM) provides a 5 V reference circuit to the brake booster vacuum sensor and the steering angle sensor. The brake booster vacuum sensor converts the change in vacuum levels in the brake booster into a signal voltage ranging from 0.13 - 3.30 V and is monitored by EBCM.

Ignition ON.

The brake booster sensor signal voltage is not within 0.13 - 3.30 V for more than 1 second.

1. The condition for the DTC is no longer present.
2. The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Schematic Reference

Hydraulic Brake Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Brake Assist System Description and Operation (Vacuum Assist) or Brake Assist System Description and Operation (Hydraulic Assist)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Note. If only DTC C1100 is set refer to Only DTC C1100 Set, if both DTC C0710 and C1100 are set, refer to Both DTC C0710 and C1100 Set.

Only DTC C1100 Set

1. Ignition OFF, disconnect the harness connector at the brake booster vacuum sensor.
2. Wait for 60 seconds, test for less than 11 ohms between the low reference circuit terminal 2 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.
3. Ignition ON, test for 4.8 - 5.2 V between the 5 V reference circuit terminal 3 and ground. If less than the specified range, test the 5 V reference circuit for an open/high resistance. If the circuit tests normal, replace the replace the EBCM. If greater than the specified range, test the 5 V reference circuit for a short to B+. If the circuit tests normal, replace the EBCM.
4. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 3 and the signal circuit terminal 1. If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the EBCM. If greater than the specified range, test the signal circuit for a short to B+. If the circuit tests normal, replace the EBCM.
5. Ignition OFF, disconnect the harness connector at the EBCM.
6. Test for infinite resistance between the signal circuit terminal 1 and ground. If not the specified value, test the signal circuit for a short to ground.
7. If all circuits test normal, test or replace the brake booster vacuum sensor.

Both DTC C0710 and C1100 Set

1. Ignition OFF, disconnect the harness connector at the brake booster vacuum sensor and the steering angle sensor.
2. Ignition ON, test for 4.8 - 5.2 V between the 5 V reference circuit terminals listed below and ground. Terminal 3 at the brake booster vacuum sensor Terminal 1 at the steering angle sensor If less than the specified range, test both 5 V reference circuits for a short to ground. If the circuit tests normal, replace the EBCM. If greater than the specified range, test both 5 V reference circuits for a short to voltage. If the circuits test normal, replace the EBCM.
3. If all circuits test normal, test or replace the brake booster vacuum sensor or steering angle sensor as required.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Power Brake Booster Vacuum Sensor Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
2. «Steering Wheel Position Sensor Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/steering-column-switches/#steering-wheel-steering-column)
3. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for EBCM replacement, setup, and programming

Symptoms - Hydraulic Brakes

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the Hydraulic Brake System. Refer to «Checking Aftermarket Accessories»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Brake Warning Indicator Malfunction»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
2. «Brake Pulsation»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-pulsation)
3. «Brake System Noise»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-noise)
4. «Braking Action Uneven - Pulls to One Side»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
5. «Braking Action Uneven - Front to Rear»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
6. «Brake Pedal Excessive Travel (Non-Hybrid)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-pedal-excessive-travel-non-hybrid) or «Brake Pedal Excessive Travel (Two-mode Hybrid)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-pedal-excessive-travel-two-mode-hybrid)
7. «Brake Pedal Excessive Effort»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-pedal-excessive-effort)
8. «Brakes Drag»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brakes-drag)
9. «Brake System Slow Release»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-slow-release)
10. «Brake Fluid Loss»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-fluid-loss)
11. «Brakes Self Apply When Turning Steering Wheel»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brakes-self-apply-when-turning-steering)
12. «Hydraulic Brake System Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
13. «Brake Assist System Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-assist-system-diagnosis)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The instrument panel cluster (IPC) sees the brake fluid level switch input opens and illuminates the Red Brake Warning indicator. The body control module (BCM) sees the park brake switch input grounded, it sends a serial data message to the IPC requesting illumination of the Red Brake Warning indicator.

Schematic Reference

Hydraulic Brake Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Brake Warning System Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Verify the park brake is released and the brake fluid is at or above the proper level. If low, refer to «Brake Fluid Loss»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-fluid-loss) .
2. Command the IPC display test with a scan tool, the warning indicator should turn ON. If the red brake warning indicator does not illuminate, replace the IPC.
3. Ignition ON, observe the scan tool BCM Park Brake Switch parameter while applying and releasing the park brake. The parameter should cycle between Applied and Release. If the parameter does not cycle between the specified values, refer to Park Brake Switch Malfunction.
4. Observe the scan tool IPC Brake Fluid parameter. The reading should be OK. If not the specified value, refer to Brake Fluid Level Switch Malfunction.

Park Brake Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the park brake switch.
2. Ignition ON, verify the scan tool BCM Park Brake Switch parameter is Released. If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM.
3. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool BCM Park Brake Switch parameter is Applied. If not the specified value, test the signal circuit for a short to voltage or an open/high resistance.
4. If all circuits test normal, test or replace the park brake switch.

Brake Fluid Level Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the brake fluid level switch.
2. Test for less than 1 ohm between the ground circuit terminal A and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool IPC Brake Fluid parameter is Ok. If not the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the IPC.
4. Install a 3A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool IPC Brake Fluid parameter is Low. If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the IPC.
5. If all circuits test normal, test or replace the brake fluid level switch.

Park Brake Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the park brake switch.
2. Test for infinite resistance between the signal terminal A and ground with the park brake released. If less than the specified value, replace the park brake switch.
3. Test for less than 1 ohm between the signal terminal A and ground with the park brake applied. If greater than the specified range, replace the park brake switch.

Brake Fluid Level Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the brake fluid level switch.
2. Test for infinite resistance between the ground terminal A and the signal terminal B. If less than the specified value, replace the brake fluid level switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Brake Fluid Level Indicator Switch Replacement (Two-mode Hybrid)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Brake Fluid Level Indicator Switch Replacement (JD9, JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
2. «Parking Brake Indicator Switch Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/parking-brake-system/#parking-brake-system)
3. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM and IPC replacement, setup, and programming

Brake Pulsation

Brake System Noise

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 4: Suspension components that are not operating properly may cause a disturbance to the vehicle during application of the brake system.
2. 5: Steering components that are not operating properly may cause a disturbance to the vehicle during application of the brake system.

Test Descriptions

The number below refers to the step number on the diagnostic table.

1. 4: Suspension components that are not operating properly may cause a disturbance to the vehicle during application of the brake system.

Brake Pedal Excessive Travel (Non-Hybrid)

Brake Pedal Excessive Travel (Two-mode Hybrid)

Brake Pedal Excessive Effort

Brakes Drag

Brake System Slow Release

Brake Fluid Loss

Brakes Self Apply When Turning Steering Wheel

The numbers below refer to the step numbers on the diagnostic table

1. 9: Lubricant leaks from non-brake system components may come in contact with and contaminate brake system components.
2. 10: Lubricant leaks from non-brake system components may come in contact with and contaminate brake system components.
3. 12: Disc brake rotor shields/backing plates that come in contact with disc brake rotors may cause brake system noise.
4. 15: Disc brake rotor thickness variation that exceeds the maximum acceptable level can cause brake pulsation.
5. 19: Disc brake rotor thickness variation that exceeds the maximum acceptable level can cause brake pulsation.
6. 22: Disc brake rotor assembled lateral runout (LRO) that exceeds the maximum acceptable level can lead to thickness variation.

Brake Hydraulic and Assist System Diagnosis (Two-mode Hybrid)

Brake Assist System Diagnosis

Preliminary Inspections

1. Visually inspect easily accessible brake system components for obvious damage and/or leaks which may indicate that the vehicle should not be driven until further inspections have been completed.
2. Inspect the brake master cylinder reservoir fluid level and adjust only if necessary for brake system road testing. Refer to «Master Cylinder Reservoir Filling»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .
3. Inspect the tire inflation pressures and adjust as necessary.
4. Inspect the tire tread patterns to ensure that they are the same or very similar, especially per axle.
5. Ensure that the vehicle is not loaded unevenly prior to brake system road testing.

Road Testing Procedure

1. Start the engine and allow it to idle.
2. Check to see if the brake system warning lamp remains illuminated.
3. If the brake system warning lamp remains illuminated, DO NOT proceed to test drive the vehicle until it is diagnosed and repaired. Refer to «Symptoms - Hydraulic Brakes»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__symptoms-hydraulic-brakes) .
4. Select a smooth, dry, clean and level road or large lot that is as free of traffic and obstacles as possible for brake system low speed road testing.
5. With the transmission in PARK, lightly apply the brake pedal. Observe both the pedal feel and the pedal travel.
6. If the brake pedal apply felt spongy, or the pedal travel was excessive, DO NOT drive the vehicle until it is repaired.
7. If the brake pedal apply did not feel spongy and the pedal travel was not excessive, proceed to step 8.
8. Release and apply the brakes.
9. While continuing to apply the brakes, shift the transmission into DRIVE, release the brakes and allow the engine to idle the vehicle away from the stopped position. Observe for a slow release of the brake system.
10. With the aid of an assistant to observe the vehicle's performance from outside of the vehicle, drive the vehicle at a low speed and lightly apply the brakes while driving past the assistant. Have the assistant observe for brake system noise from the side of the vehicle closest to them, while you observe both the pedal effort and the pedal travel.
11. If the brake pedal apply effort was excessive, or the pedal travel was excessive, DO NOT continue to test drive the vehicle until it is repaired.
12. If the brake pedal apply effort was not excessive and the pedal travel was not excessive, proceed to step 13.
13. Drive the vehicle in the opposite direction, at the same low speed and lightly apply the brakes while driving past the assistant. Have the assistant observe for brake system noise from the side of the vehicle closest to him.
14. Drive the vehicle at a low speed and shift the transmission into NEUTRAL without applying the brakes. Observe for a rapid deceleration in vehicle speed, indicating possible brake drag.
15. Select a smooth, dry, clean and level road that is as free of heavy traffic as possible for brake system moderate speed road testing.
16. Drive the vehicle at a moderate speed. Observe for a pull and/or incorrect tracking of the vehicle without the brakes applied.
17. While continuing to drive the vehicle at a moderate speed, perform several light applies of the brakes. Observe the pedal effort and the pedal travel, observe for brake system noise, pulsation and/or brake drag.
18. If the brake pedal apply effort was excessive, or the pedal travel was excessive, DO NOT continue to test drive the vehicle until it is repaired.
19. If the brake pedal apply effort was not excessive and the pedal travel was not excessive, proceed to step 20.
20. While continuing to drive the vehicle at a moderate speed, perform several moderate applies of the brakes. Observe the pedal effort and the pedal travel, observe for brake system pulsation and/or uneven braking action - either side to side, or front to rear. A small amount of vehicle front end dip is expected during a moderate apply of the brakes.
21. If the brake pedal apply effort was excessive, or the pedal travel was excessive, DO NOT continue to test drive the vehicle until it is repaired.

Special Tools

J 28662 Brake Pedal Effort Gauge. See Special Tools .

1. With the ignition OFF and the brakes cool, apply the brakes 3-5 times, or until the brake pedal becomes firm, in order to deplete the brake booster power reserve.
2. Install the J 28662 to the brake pedal. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
3. Measure and record the distance (1) from the brake pedal to the rim of the steering wheel; note the points of measurement.
4. Apply and maintain the brakes with 445 N (100 lb) of force to the brake pedal, as indicated on the J 28662 . See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
5. While maintaining 445 N (100 lb) of force to the brake pedal, measure and record the distance (2) from the same point on the brake pedal to the same point on the rim of the steering wheel.
6. Release the brakes and repeat steps 4 and 5 to obtain a second measurement. After obtaining a second measurement, proceed to step 7.
7. Average the first and second measurements recorded during the two applies of the brakes.
8. Subtract the initial measurement, unapplied (1), from the averaged, applied measurement (2) to obtain the brake pedal travel distance. Specification: Vacuum assist equipped, maximum brake pedal travel (measured with the ignition OFF, brake booster power assist depleted, and the brakes cool): 60 mm (2.36 in) Hydraulic assist equipped, maximum brake pedal travel (measured with the ignition OFF, brake booster power assist depleted, and the brakes cool): 90 mm (3.54 in)

Brake Pedal Travel Measurement and Inspection (Two-mode Hybrid)

Note. The brake corners must be cool to obtain the most accurate measurement.

1. Place the transmission in PARK.
2. Turn the ignition OFF, without pausing at ACCESSORY, and without applying the brake pedal. Remove the ignition key.
3. Wait approximately 1-3 minutes until the brake modulator and HPA pressure relief is complete.
4. Inspect the battery state of charge. Refer to «Battery Inspection/Test»(/cadillac/escalade/gmt900-2006-2014/remont/charging-system/#battery-charging-system-and-starting-system) .
5. If necessary, connect a battery charger to the 12V battery. Refer to «Battery Charging»(/cadillac/escalade/gmt900-2006-2014/remont/charging-system/#battery-charging-system-and-starting-system) .
6. Install a scan tool to the vehicle.
7. Turn the ignition ON with the engine OFF.
8. Using the scan tool, perform the following steps: Select Diagnostics Select the appropriate vehicle information Select Chassis Select Electronic Brake Control Module (EBCM) Select Data Display Scroll through the Data List, select and accept Brake Master Cylinder (BMC) Primary Piston Reference Position, and Master Cylinder Pressure Sensor
9. While observing the master cylinder pressure on the scan tool data display, using moderate speed and moderate effort, press the brake pedal to a force of 5000 kPa (725 psi).
10. Record the distance the displayed on the scan tool that the BMC primary piston has travelled at a pedal apply force of 5000 kPa (725 psi).
11. Release the brake pedal.
12. Wait 15 seconds, then repeat steps 9-11 to obtain a second measurement.
13. Compute the average of the first and second measurements recorded during the brake applies. Specification: Maximum brake master cylinder (BMC) primary piston travel, (measured with the ignition ON, engine OFF and the brakes cool), at a brake pedal apply force of 5000 kPa (725 psi): 18 mm (0.71 in)

Brake System Vacuum Source Test

1. Disconnect the engine vacuum hose from the vacuum brake booster check valve.
2. Install a vacuum gauge to the engine vacuum hose.
3. Start the engine and allow the engine to idle until normal operating temperatures are reached.
4. With the vehicle in PARK, the engine idling, and the air conditioning (A/C) system OFF, check to see if the engine vacuum reading is within the specified normal engine vacuum range. Specification: 47-68 kPa (14-20 in Hg)
5. Turn the ignition OFF.
6. If the engine vacuum reading was within the specified normal range, proceed to step 10.
7. If the engine vacuum reading was NOT within the specified normal range, inspect the engine vacuum hose for the following conditions: Loose connection to the engine Collapse, deformation or contamination Cracks, cuts, dry-rot
8. If any of these conditions were found with the engine vacuum hose, replace the hose, then repeat steps 2-4.
9. If none of these conditions were found with the engine vacuum hose, then there is an engine vacuum source problem, check the engine vacuum system.
10. Remove the vacuum brake booster check valve from the booster.
11. Install the check valve to the engine vacuum hose.
12. Install the vacuum gauge to the check valve.
13. Start the engine and allow the engine to idle in PARK with the A/C system OFF, until normal operating temperatures are reached.
14. Turn the ignition OFF.
15. Check to see if the engine vacuum reading is maintained within the specified normal engine vacuum range. Specification: 47-68 kPa (14-20 in Hg)
16. If the engine vacuum reading is maintained within the specified normal range, proceed to step 18.
17. If the engine vacuum reading is NOT maintained within the specified normal range, replace the brake booster check valve, then repeat steps 11-15.
18. Inspect the brake booster check valve grommet for the following conditions: Loose connection to the vacuum brake booster Deformation or contamination Cracks, cuts, dry-rot
19. If any of these conditions were found with the check valve grommet, replace the grommet.

Scheme 2

1. Check the power steering system fluid level and adjust as necessary. Refer to «Checking and Adding Power Steering Fluid (Without Hydroboost)»(/cadillac/escalade/gmt900-2006-2014/remont/electronic-steering/#power-steering-system__checking-and-adding-power-steering-fluid) or «Checking and Adding Power Steering Fluid (With Hydroboost)»(/cadillac/escalade/gmt900-2006-2014/remont/electronic-steering/#power-steering-system__checking-and-adding-power-steering-fluid) .
2. Clean any fluid from the following areas: The power steering hose fittings (1) The power steering hose ports (3) The joint between the power brake booster housing and end cap (4) The joint between the power brake booster housing and the master cylinder (5) The end cap The power steering inlet and outlet hoses at the crimp joints (6)
3. Start the engine and allow the power steering fluid to reach operating temperature.
4. Allow the engine to idle and slowly apply the brake pedal to run-out, holding until the power steering pump reaches the pressure relief valve setting and hisses. Maintain the brake pedal force approximately two seconds, then release the brake pedal.
5. With the brakes fully released, allow the engine to idle for fifteen seconds.
6. Repeat steps 4 and 5 four times.
7. With the engine idling, turn the steering wheel from stop to stop four times holding the steering wheel at each stop for two seconds.
8. Increase the engine speed to approximately 1,000 RPM and turn the steering wheel approximately every one second. Do not hold the steering wheel at full stop.
9. Allow the engine to idle without pressure applied to the brake pedal for thirty seconds.
10. With the engine idling, apply the brake pedal to run-out and hold the pedal force at run-out for approximately one second and then release the brake pedal.
11. Repeat steps 7 through 10 four times.
12. Allow the engine to idle for thirty seconds and then turn the engine OFF.
13. Inspect the power brake booster, the power steering hose fitting ports (3), and the power steering inlet and outlet hoses at the crimp joints (6) for any leaks.
14. If there are leaks at the power steering inlet and/or outlet hoses at the crimp joints, the affected power steering hose requires replacement.
15. If there are leaks at the power steering hose fittings (1) to the hydraulic booster ports (3), perform the following steps: Tighten the leaking power steering hose assembly fittings to the proper specifications Inspect again for fluid leaks at the affected locations
16. If there are leaks at the power steering hose fittings after tightening the fittings, perform the following steps: At each affected location, disconnect the power steering hose fitting Inspect the sealing end of the power steering hose fitting for damage and replace the hose if damaged Install a new O-ring seal (2) to the power steering hose Install the power steering hose and tighten the fitting to the proper specification Inspect again for fluid leaks at the affected location
17. If the power brake booster is leaking, replace the power brake booster. Refer to «Power Brake Booster Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__power-brake-booster-replacement) .
18. If brake fluid is leaking, refer to «Brake Fluid Loss»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-fluid-loss) .

Tools Required

J 28662 Brake Pedal Effort Gauge. See Special Tools .

Inspection

1. Install the J 28662 to the brake pedal. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
2. Start the engine and allow it to idle. Ensure that the wheels are directed straight ahead.
3. Apply and maintain the brakes with 111 N (25 lb) of force to the brake pedal, as indicated on the J 28662 . See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) . Observe for noises.
4. Quickly release the brakes. Observe for noises.
5. If chatter and/or a vibration of the brake pedal was apparent during the brake system apply of 111 N (25 lb) of force, the power steering pump drive belt not may have proper tension or may be excessively worn.
6. If any significant noise was apparent during the quick release of the brakes following the brake system apply of 111 N (25 lb) of force, there is likely a restriction in the hydraulic brake booster power steering return hose.
7. Apply the brakes with 178 N (40 lb) of force to the brake pedal, as indicated on the J 28662 , then gradually increase pedal effort up to 445 N (100 lb) of force for not more than 5 seconds at a time. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) . Observe for noises.
8. Quickly release the brakes. Observe for noises.
9. If a hiss noise was apparent and increased during the brake system increasing apply of 178-445 N (40-100 lb) of force, the hydraulic brake booster assist system is operating normally from an audible standpoint.
10. If a clunk, chatter, and/or clicking noise was apparent during the quick release of the brakes following the brake system increasing apply of 178-445 N (40-100 lb) of force, the hydraulic brake booster assist system is operating normally from an audible standpoint.

Brake System External Leak Inspection

1. In order to inspect for external brake fluid leaks, first check the fluid level in the master cylinder. While a slight brake fluid level drop can be considered a normal condition due to brake lining wear, a very low level may indicate a brake fluid leak in the hydraulic system.
2. If the fluid level is abnormally low, adjust the brake fluid level. Refer to «Master Cylinder Reservoir Filling»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .
3. Start the engine and allow it to idle.
4. Apply constant, moderate foot pressure to the brake pedal. If the brake pedal gradually falls away while under foot pressure, there may be a brake fluid leak.
5. Turn OFF the ignition.
6. Visually inspect the following brake system components for brake fluid leaks, excessive corrosion, and damage. Give particular attention to all brake pipe and flexible hose connections to ensure that there are not any slight brake fluid leaks - even though the brake pedal may feel firm and hold steady: Master cylinder brake pipe fittings All brake pipe connections Brake pipes Brake hoses and connections Brake calipers and/or wheel cylinders, if equipped
7. While slight dampness around the master cylinder reservoir can be considered acceptable, brake fluid leaking from any of the brake system components requires immediate attention. If any of these components exhibit signs of brake fluid leakage, repair or replace those components. After the repair or replacement, reinspect the hydraulic brake system to assure proper function.

Brake System Internal Leak Test (Two-mode Hybrid)

1. Ensure is ignition is OFF for at least 60 seconds to allow the system to depressurize and deplete the power reserve.
2. Apply the brake pedal several times to verify the power reserve is fully depleted.
3. Apply light, steady pressure to the brake pedal. Observe both the brake pedal feel and travel.
4. Release the brake pedal.
5. If the brake pedal apply felt spongy, but the brake pedal travel was not excessive, perform the following steps: Inspect the brake system for external leaks. Refer to «Brake System External Leak Inspection»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-external-leak-inspection) . Pressure bleed the brake system in order to purge any air that may be trapped in the system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
6. If the brake pedal apply did not feel spongy, but the brake pedal travel was excessive, perform the following steps: Loosen the master cylinder-to-adapter mounting nuts. Carefully pull the master cylinder away from the adapter just enough to inspect the mounting surface of the master cylinder. Inspect the master cylinder mounting surface at the primary piston (2) for brake fluid leaks.
7. If the master cylinder exhibits any leakage around the primary piston (2), then the primary piston primary seal (4) and/or secondary seal (3) is leaking and the master cylinder requires replacement.
8. If the master cylinder primary piston (2) does not exhibit any leakage, install the master cylinder to the adapter and pressure bleed the brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
9. If the brake pedal apply did not feel spongy, and the brake pedal travel was initially steady and not excessive, but then gradually fell, then the master cylinder requires replacement due to an internal leak past a piston seal.
10. If the brake pedal apply did not feel spongy, and the brake pedal travel was initially steady and not excessive, then fell slightly, then became steady again, then the brake pressure modulator valve (BPMV) may be leaking internally, and may require replacement.

Brake System Internal Leak Test (Non-Hybrid)

1. Start the engine and allow it to idle.
2. Apply light, steady pressure to the brake pedal. Observe both the brake pedal feel and travel.
3. Release the brakes and turn OFF the ignition.
4. If the brake pedal apply felt spongy, but the brake pedal travel was not excessive, perform the following steps: Inspect the brake system for external leaks. Refer to «Brake System External Leak Inspection»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-external-leak-inspection) . Pressure bleed the brake system in order to purge any air that may be trapped in the system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
5. If the brake pedal apply did not feel spongy, but the brake pedal travel was excessive, perform the following steps: Loosen the master cylinder-to-brake power booster mounting nuts. Carefully pull the master cylinder away from the brake power booster just enough to inspect the mounting surface of the master cylinder. Inspect the master cylinder mounting surface at the primary piston (2) for brake fluid leaks.
6. If the master cylinder exhibits any leakage around the primary piston (2), then the primary piston primary seal (4) and/or secondary seal (3) is leaking and the master cylinder requires overhaul or replacement.
7. If the master cylinder primary piston (2) does not exhibit any leakage, pressure bleed the brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
8. If the brake pedal apply did not feel spongy, and the brake pedal travel was initially steady and not excessive, but then gradually fell, then the master cylinder requires overhaul or replacement due to an internal leak past the secondary piston (1) from the secondary piston primary seal (6) or secondary seal (5).
9. If the brake pedal apply did not feel spongy, and the brake pedal travel was initially steady and not excessive, then fell slightly, then became steady again, then the brake pressure modulator valve (BPMV) may be leaking internally, and may require replacement.

Hydraulic Brake Component Operation Visual Inspection

1. With the tire and wheel assemblies removed and the brake rotors retained by wheel lug nuts, visually inspect the caliper piston dust boot (2) sealing area to ensure that there are no brake fluid leaks.
2. If any evidence of a brake fluid leak is present, the brake caliper requires overhaul or replacement.
3. While the brake system is at rest (4), observe the position of the caliper piston (1) in relation to the caliper housing.
4. Have an assistant apply and release the brake pedal several times while you observe the operation of the hydraulic brake caliper. Observe the caliper piston (1) for unrestricted and even movement during each apply of the brake system (5). Observe the caliper piston (1) for an unrestricted and even return motion during each release of the brake system (6).
5. If the caliper piston (1) did not exhibit unrestricted and even movement during brake system apply and/or release, the piston square seal (3) may be worn or damaged and the caliper may require overhaul or replacement.

Brake Pipe and Hose Inspection

1. Visually inspect all of the brake pipes for the following conditions: Kinks, improper routing, missing or damaged retainers Leaking fittings, excessive corrosion
2. If any of the brake pipes exhibited any of the conditions listed, then the identified pipe, or pipes, require replacement.
3. Ensure that the vehicle axles are properly supported at ride height in order to maintain the proper relationship of the flexible brake hoses to the chassis.
4. Visually inspect all of the flexible brake hoses for the following conditions: Kinks (1), improper routing, twists, chafing, missing or damaged retainers Leaking connections, cracking, dry-rot, blisters, bulges
5. If any of the flexible brake hoses exhibited any of the conditions listed, then the identified flexible brake hose, or hoses require replacement.
6. Squeeze the flexible brake hoses with firm finger pressure to check for soft spots (2), indicating an internal restriction. Check the entire length of each flexible brake hose.
7. If any of the flexible brake hoses were found to have soft spots (2), then the identified flexible brake hose, or hoses require replacement.

Brake Pedal Pushrod Inspection

1. Disconnect the brake pedal pushrod (1) from the brake pedal.
2. Inspect the brake pedal pushrod eyelet bushing (2), if equipped, for cracks and/or excessive wear.
3. Reposition the pedal pushrod boot (3) toward the front of the vehicle to expose as much of the pedal pushrod (1) as possible.
4. Inspect the brake pedal pushrod (1) for straightness.
5. If the brake pedal pushrod eyelet bushing (2) exhibited cracks and/or excessive wear, then the bushing requires replacement.
6. If the brake pedal pushrod (1) is not straight, then the pushrod requires replacement.
7. Return the pedal pushrod boot (3) to its original position on the pedal pushrod (1).
8. Connect the brake pedal pushrod (1) to the brake pedal.

Master Cylinder Reservoir Filling

1. Visually inspect the brake fluid level through the brake master cylinder reservoir.
2. If the brake fluid level is at or below the half-full point during routine fluid checks, the brake system should be inspected for wear and possible brake fluid leaks.
3. If the brake fluid level is at or below the half-full point during routine fluid checks, and an inspection of the brake system did not reveal wear or brake fluid leaks, the brake fluid may be topped-off up to the maximum-fill level.
4. If brake system service was just completed, the brake fluid may be topped-off up to the maximum-fill level.
5. If the brake fluid level is above the half-full point, adding brake fluid is not recommended under normal conditions.
6. If brake fluid is to be added to the master cylinder reservoir, clean the outside of the reservoir on and around the reservoir cap prior to removing the cap and diaphragm. Use only Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.

Removal Procedure

1. Turn the ignition to OFF, without pausing at ACCESSORY, and remove the ignition key.
2. Wait approximately 1 to 3 minutes until the brake modulator and HPA pressure relief is complete.
3. Remove the brake fluid from the brake master cylinder reservoir and discard into an approved container.
4. Disconnect the brake fluid level sensor electrical connector.
5. Disconnect the brake master cylinder reservoir return hose quick connect (1) and position the hose aside.
6. Disconnect the brake master cylinder reservoir supply hose quick connect (2) and position the hose aside.
7. Remove the brake master cylinder reservoir pins (1).
8. Lift the master cylinder reservoir (1) straight up and remove the reservoir from the master cylinder.
9. Remove the 3 master cylinder reservoir seals (1).

Installation Procedure

1. Install the 3 master cylinder reservoir seals (1). Lubricate the master cylinder reservoir seals and the outer surface area of the reservoir-to-housing barrels with Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667) or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
2. Install the master cylinder reservoir (1) to the master cylinder. Ensure the master cylinder reservoir is seated fully into the master cylinder by pressing the reservoir straight down into the master cylinder.
3. Install the brake master cylinder reservoir pins (1) and tighten to 8 N.m (71 lb in).
4. Connect the brake master cylinder reservoir return hose quick connect (1).
5. Connect the brake master cylinder reservoir supply hose quick connect (2).
6. Connect the brake fluid level sensor electrical connector.
7. Fill the brake master cylinder reservoir. Refer to «Master Cylinder Reservoir Filling»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .

Scheme 3

1. Using a suitable tool, remove the brake fluid from the brake master cylinder reservoir.
2. Discard the brake fluid into an approved container.
3. Disconnect the brake fluid level indicator switch electrical connector.
4. Remove the master cylinder reservoir bolts (1).
5. Carefully lift the master cylinder reservoir (1) straight upward and remove the reservoir from the master cylinder.
6. Remove the master cylinder reservoir seals (1).

1. Lubricate the master cylinder reservoir seals (1) and the outer surface area of the reservoir-to-housing barrels with GM approved brake fluid from a clean, sealed brake fluid container.
2. If reinstalling the master cylinder reservoir, clean the reservoir with denatured alcohol, or equivalent and allow to dry.
3. Install the master cylinder reservoir seals to the master cylinder. Ensure the master cylinder reservoir seals are fully seated in the master cylinder body.
4. Lubricate the master cylinder reservoir-to-master cylinder barrels with GM approved brake fluid from a clean, sealed brake fluid container.
5. Carefully press the master cylinder reservoir (1) straight downward and install the reservoir to the master cylinder.
6. Install the master cylinder reservoir bolts (1) and tighten to 8 N.m (71 lb in).
7. Connect the brake fluid level indicator switch electrical connector.
8. Fill the master cylinder reservoir. Refer to «Master Cylinder Reservoir Filling»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .

Scheme 4

Scheme 5

1. Turn the ignition to OFF, without pausing at ACCESSORY, and remove the ignition key.
2. Wait approximately 1 to 3 minutes until the brake modulator and HPA pressure relief is complete.
3. Remove the brake fluid from the brake master cylinder reservoir and discard into an approved container.
4. Disconnect the brake fluid level sensor electrical connector.
5. Disconnect the brake master cylinder reservoir return hose quick connect (1) and position the hose aside.
6. Disconnect the brake master cylinder reservoir supply hose quick connect (2) and position the hose aside.
7. Disconnect the brake master cylinder primary brake pipe fitting (1). Cap the brake pipe fitting and plug the master cylinder outlet port to prevent brake fluid loss and contamination.
8. Disconnect the brake master cylinder left supply brake pipe fitting (1). Cap the brake pipe fitting and plug the master cylinder outlet port to prevent brake fluid loss and contamination.
9. Disconnect the brake master cylinder right supply brake pipe fitting (1). Cap the brake pipe fitting and plug the master cylinder outlet port to prevent brake fluid loss and contamination.
10. Disconnect the brake master cylinder right front brake pipe fitting (1). Cap the brake pipe fitting and plug the master cylinder outlet port to prevent brake fluid loss and contamination.
11. Disconnect the brake master cylinder left front brake pipe fitting (1). Cap the brake pipe fitting and plug the master cylinder outlet port to prevent brake fluid loss and contamination.
12. Remove the brake master cylinder nuts (1). Discard the brake master cylinder nuts.
13. Remove the brake master cylinder and the master cylinder seal (1).

1. Bench bleed the master cylinder. Refer to «Master Cylinder Bench Bleeding»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-bench-bleeding) .
2. Install the brake master cylinder seal (1) and the master cylinder to the adapter. Ensure the brake master cylinder seal is fully seated in the groove on the master cylinder housing.
3. Install 2 new brake master cylinder nuts (1) and tighten to 33 N.m (24 lb ft).
4. Connect the brake master cylinder left front brake pipe fitting (1) and tighten to 30 N.m (22 lb ft).
5. Connect the brake master cylinder right front brake pipe fitting (1) and tighten to 30 N.m (22 lb ft).
6. Connect the brake master cylinder right supply brake pipe fitting (1) and tighten to 30 N.m (22 lb ft).
7. Connect the brake master cylinder left supply brake pipe fitting (1) and tighten to 30 N.m (22 lb ft).
8. Connect the brake master cylinder primary brake pipe fitting (1) and tighten to 30 N.m (22 lb ft).
9. Connect the brake master cylinder reservoir return hose quick connect (1).
10. Connect the brake master cylinder reservoir supply hose quick connect (2).
11. Connect the brake fluid level sensor electrical connector.
12. Fill the brake master cylinder reservoir. Refer to «Master Cylinder Reservoir Filling»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .
13. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .

1. Place the transmission in the PARK or NEUTRAL position.
2. Apply the park brake.
3. Turn the ignition to OFF, without pausing at ACCESSORY, and without applying the brake pedal. Remove the ignition key.
4. Wait approximately 1 to 3 minutes until the brake modulator and HPA pressure relief is complete.
5. Remove the master cylinder nuts (1). Discard the master cylinder nuts.
6. Without disconnecting the brake pipes, release and carefully position aside the master cylinder (1). Support the master cylinder with heavy mechanics wire or equivalent.
7. Inspect the master cylinder seal (1) for damage and replace, if necessary.
8. Disconnect the brake master cylinder (BMC) primary piston position sensor electrical connector.
9. Remove the brake pushrod retainer bolt (1), if equipped.
10. Remove the brake pushrod retainer (1).
11. Slide the stoplamp switch (1) off of the brake pedal pushrod pin while simultaneously disconnecting the brake pushrod.
12. Remove the 4 brake pedal bracket nuts (1).
13. Remove the brake master cylinder adapter (1).
14. Inspect the master cylinder adapter gasket for damage and replace, if necessary.

1. Install the master cylinder adapter gasket, if removed.
2. Install the brake master cylinder adapter (1).
3. Install the 4 brake pedal bracket nuts (1) and tighten to 25 N.m (18 lb ft).
4. Connect the brake pedal pushrod while simultaneously installing the stoplamp switch (1).
5. Install the brake pushrod retainer (1). Rotate the brake pushrod retainer 360 degrees to ensure the retainer is fully engaged in the brake pedal pushrod pivot pin groove.
6. Install the brake pushrod retainer bolt (1), if equipped and tighten to 10 N.m (89 lb in).
7. Connect the BMC primary piston position sensor electrical connector.
8. Install the master cylinder seal (1), if removed. Ensure the brake master cylinder seal is fully seated in the groove on the master cylinder housing.
9. Position the master cylinder (1) to the master cylinder adapter.
10. Install 2 new master cylinder nuts (1) and tighten to 33 N.m (24 lb ft).
11. Inspect the battery state of charge. Refer to «Battery Inspection/Test»(/cadillac/escalade/gmt900-2006-2014/remont/charging-system/#battery-charging-system-and-starting-system) .
12. If necessary, connect a battery charger to the 12V battery. Refer to «Battery Charging»(/cadillac/escalade/gmt900-2006-2014/remont/charging-system/#battery-charging-system-and-starting-system) .
13. Install a scan tool to the vehicle.
14. Turn the ignition ON with the engine OFF.
15. Using the scan tool, perform the following steps: Select Diagnostics Select the appropriate vehicle information Select Chassis Select Electronic Brake Control Module (EBCM) Select Module Setup Select BMC Primary Piston Position Relearn and follow the instructions on the scan tool

Master Cylinder Bench Bleeding

1. Secure the mounting flange of the brake master cylinder in a bench vise so that the rear of the primary piston is accessible.
2. Remove the master cylinder reservoir cap and diaphragm.
3. Install suitable fittings to the master cylinder ports that match the type of flare seat required and also provide for hose attachment.
4. Install transparent hoses to the fittings installed to the master cylinder ports, then route the hoses into the master cylinder reservoir.
5. Fill the master cylinder reservoir to at least the half-way point with GM approved brake fluid from a clean, sealed brake fluid container. Refer to «Master Cylinder Reservoir Filling»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .
6. Ensure that the ends of the transparent hoses running into the master cylinder reservoir are fully submerged in the brake fluid.
7. Using a smooth, round-ended tool, depress and release the primary piston as far as it will travel, a depth of about 25 mm (1 in), several times. Observe the flow of fluid coming from the ports. As air is bled from the primary and secondary pistons, the effort required to depress the primary piston will increase and the amount of travel will decrease.
8. Continue to depress and release the primary piston until fluid flows freely from the ports with no evidence of air bubbles.
9. Remove the transparent hoses from the master cylinder reservoir.
10. Install the master cylinder reservoir cap and diaphragm.
11. Remove the fittings with the transparent hoses from the master cylinder ports. Wrap the master cylinder with a clean shop cloth to prevent brake fluid spills.
12. Remove the master cylinder from the vise.

Scheme 6

Scheme 7

Scheme 8

J 45405 Pipe Flaring Tool Kit. See Special Tools .

Replacement

1. Inspect the area of brake pipe to be repaired or replaced.
2. Release the brake pipe to be replaced from the retainers, as required.
3. Select an appropriate location to section the brake pipe, if necessary. Allow adequate clearance in order to maneuver the J 45405 . See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) . Avoid sectioning the brake pipe at bends or mounting points.
4. Using a string or wire, measure the length of the pipe to be replaced including all pipe bends.
5. Add to the measurement taken the appropriate additional length required for each flare to be created. Specification: 6.35 mm (0.250 in) for 4.76 mm (3/16 in) diameter pipe 9.50 mm (0.374 in) for 6.35 mm (1/4 in) diameter pipe 12.67 mm (0.499 in) for 7.94 mm (5/16 in) diameter pipe
6. Using the pipe cutter included in the J 45405 , carefully cut the brake pipe squarely to the measured length. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
7. Remove the sectioned brake pipe from the vehicle.
8. Select the appropriate size of brake pipe and tube nuts, as necessary. The brake pipe outside diameter determines brake pipe size.
9. Strip the nylon coating from the brake pipe end to be flared, if necessary. Select the appropriate blade on the coating stripping tool included in the J 45405 , by unthreading the blade block from the stripping tool and installing the block with the desired blade facing the tool rollers. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) . Specification: 6.35 mm (0.250 in) blade for 4.76 mm (3/16 in) diameter pipe 9.50 mm (0.374 in) blade for 6.35 mm (1/4 in) and 7.94 mm (5/16 in) diameter pipe Insert the brake pipe end to be flared into the stripping tool to the depth of the ledge on the tool rollers. While holding the brake pipe firmly against the stripping tool roller ledges, rotate the thumbwheel of the tool until the blade contacts the brake pipe coated surface. NOTE: Do not gouge the metal surface of the brake pipe. Rotate the stripping tool in a clockwise direction, ensuring that the brake pipe end remains against the tool roller ledges. After each successive revolution of the stripping tool, carefully rotate the thumbwheel of the tool clockwise, in order to continue stripping the coating from the brake pipe until the metal pipe surface is exposed. Loosen the thumbwheel of the tool and remove the brake pipe. NOTE: Ensure that all loose remnants of the nylon coating have been removed from the brake pipe. Inspect the stripped end of the brake pipe to ensure that the proper amount of coating has been removed. Specification: 6.35 mm (0.250 in) for 4.76 mm (3/16 in) diameter pipe 9.50 mm (0.374 in) for 6.35 mm (1/4 in) and 7.94 mm (5/16 in) diameter pipe
10. Chamfer the inside and outside diameter of the pipe with the de-burring tool included in the J 45405 . See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
11. Install the tube nuts on the brake pipe, noting their orientation.
12. Clean the brake pipe and the J 45405 of lubricant, contaminants, and debris. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
13. Loosen the die clamping screw of the J 45405 . See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
14. Select the corresponding die set and install the die halves into the die cage with the full, flat face of one die facing the clamping screw, and the counterbores of both dies facing the forming ram.
15. Place the flat face of an unused die (1) against the die halves in the clamping cage and hold firmly against the counterbored face of the dies.
16. Insert the prepared end of the pipe to be flared through the back of the dies until the pipe is seated against the flat surface of the unused die (1).
17. Remove the unused die (1).
18. Ensure that the rear of both dies are seated firmly against the enclosed end of the die cage.
19. Firmly hand tighten the clamping screw (2) against the dies.
20. Select the appropriate forming mandrel and place into the forming ram.
21. Rotate the hydraulic fluid control valve clockwise to the closed position.
22. Rotate the body of the J 45405 until it bottoms against the die cage. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
23. While guiding the forming mandrel into the exposed end of pipe to be flared, operate the lever of the J 45405 until the forming mandrel bottoms against the clamping dies. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
24. Rotate the hydraulic fluid control valve counterclockwise to the open position to allow the hydraulic forming ram to retract.
25. Insert the finishing cone into the forming ram.
26. Rotate the hydraulic fluid control valve clockwise to the closed position.
27. Rotate the body of the J 45405 until it bottoms against the die cage. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
28. While guiding the finishing cone into the exposed end of pipe to be flared, operate the lever of the J 45405 until the finishing cone bottoms against the dies. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
29. Rotate the hydraulic fluid control valve counterclockwise to the open position to allow the hydraulic forming ram to retract.
30. Loosen the die clamping screw and remove the dies and pipe.
31. If necessary, lightly tap the dies until the die halves separate.
32. Inspect the brake pipe flare for correct shape and diameter (a). Specification: 6.74-7.10 mm (0.265-0.279 in) flare diameter for 4.76 mm (3/16 in) diameter pipe 8.57-9.27 mm (0.344-0.358 in) flare diameter for 6.35 mm (1/4 in) diameter pipe 10.42-10.79 mm (0.410-0.425 in) flare diameter for 7.94 mm (5/16 in) diameter pipe
33. If necessary, using the removed section of brake pipe as a template, shape the new pipe with a suitable brake pipe bending tool. NOTE: When installing the pipe, maintain a clearance of 19 mm (3/4 in) from all moving or vibrating components.
34. Install the pipe to the vehicle with the appropriate brake pipe unions, as required.
35. If previously released, secure the brake pipe to the retainers.
36. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
37. With the aid of an assistant, inspect the brake pipe flares for leaks by starting the engine and applying the brakes.

1. Turn the ignition to OFF, without pausing at ACCESSORY, and remove the ignition key.
2. Wait approximately 1 to 3 minutes until the brake modulator and HPA pressure relief is complete.
3. Remove the brake fluid from the brake master cylinder reservoir until the level is below the reservoir supply hose fitting and discard into an approved container.
4. Disconnect the brake fluid level sensor electrical connector.
5. Disconnect the brake master cylinder reservoir return hose quick connect (1).
6. Disconnect the brake master cylinder reservoir supply hose quick connect (2).
7. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
8. Remove the antilock brake system (ABS) module splash shield retainers (1).
9. Remove the ABS module splash shield bolts (1).
10. Remove the ABS module splash shield (1).
11. Clean all dirt and debris from the brake pressure modulator valve (BPMV) assembly and the brake hose fittings.
12. Disconnect the BPMV supply hose quick connect (1). Cap the BPMV inlet port and plug the supply hose to prevent brake fluid loss and contamination.
13. Disconnect the BPMV return hose quick connect (1). Cap the BPMV outlet port and plug the return hose to prevent brake fluid loss and contamination.
14. Release the supply and return hoses from the retainers and remove the hoses from the vehicle.

1. Install the supply and return hoses to the vehicle and the retainers.
2. Connect the BPMV return hose quick connect (1). Ensure the return hose quick connect is fully engaged by attempting to pull the return hose from the outlet fitting.
3. Connect the BPMV supply hose quick connect (1). Ensure the supply hose quick connect is fully engaged by attempting to pull the supply hose from the inlet fitting.
4. Install the ABS module splash shield (1).
5. Install the ABS module splash shield bolts (1) and tighten to 20 N.m (15 lb ft).
6. Install the ABS module splash shield retainers (1).
7. Lower the vehicle.
8. Connect the brake master cylinder reservoir return hose quick connect (1).
9. Connect the brake master cylinder reservoir supply hose quick connect (2).
10. Fill the brake master cylinder reservoir. Refer to «Master Cylinder Reservoir Filling»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

1. Place a clean shop cloth beneath the brake master cylinder to prevent brake fluid spills.
2. With the ignition OFF and the brakes cool, apply the brakes 3-5 times, or until the brake pedal effort increases significantly, in order to deplete the brake booster power reserve.
3. If you have performed a brake master cylinder bench bleeding on this vehicle, or if you disconnected the brake pipes from the master cylinder, you must perform the following steps: Ensure that the brake master cylinder reservoir is full to the maximum-fill level. If necessary add GM approved brake fluid from a clean, sealed brake fluid container. Refer to «Fluid and Lubricant Recommendations (USA and Canada)»(/cadillac/escalade/gmt900-2006-2014/remont/lubrication-system/#maintenance-and-lubrication__fluid-and-lubricant-recommendations-usa-and) . If removal of the reservoir cap and diaphragm is necessary, clean the outside of the reservoir on and around the cap prior to removal. With the rear brake pipe installed securely to the master cylinder, loosen and separate the front brake pipe from the front port of the brake master cylinder. Allow a small amount of brake fluid to gravity bleed from the open port of the master cylinder. Reconnect the brake pipe to the master cylinder port and tighten securely. Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal. Loosen the same brake pipe to purge air from the open port of the master cylinder. Tighten the brake pipe, then have the assistant slowly release the brake pedal. Wait 15 seconds, then repeat steps 3.3-3.7 until all air is purged from the same port of the master cylinder. With the front brake pipe installed securely to the master cylinder, after all air has been purged from the front port of the master cylinder, loosen and separate the rear brake pipe from the master cylinder, then repeat steps 3.3-3.8. After completing the final master cylinder port bleeding procedure, ensure that both of the brake pipe-to-master cylinder fittings are properly tightened.
4. Fill the brake master cylinder reservoir with GM approved brake fluid from a clean, sealed brake fluid container. Refer to «Master Cylinder Reservoir Filling»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) . Ensure that the brake master cylinder reservoir remains at least half-full during this bleeding procedure. Add fluid as needed to maintain the proper level. Clean the outside of the reservoir on and around the reservoir cap prior to removing the cap and diaphragm.
5. Install a proper box-end wrench onto the RIGHT REAR wheel hydraulic circuit bleeder valve.
6. Install a transparent hose over the end of the bleeder valve.
7. Submerge the open end of the transparent hose into a transparent container partially filled with GM approved brake fluid from a clean, sealed brake fluid container. Refer to «Fluid and Lubricant Recommendations (USA and Canada)»(/cadillac/escalade/gmt900-2006-2014/remont/lubrication-system/#maintenance-and-lubrication__fluid-and-lubricant-recommendations-usa-and) .
8. Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal.
9. Loosen the bleeder valve to purge air from the wheel hydraulic circuit.
10. Tighten the bleeder valve, then have the assistant slowly release the brake pedal.
11. Wait 15 seconds, then repeat steps 8-10 until all air is purged from the same wheel hydraulic circuit.
12. With the right rear wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the right rear hydraulic circuit install a proper box-end wrench onto the LEFT REAR wheel hydraulic circuit bleeder valve.
13. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
14. With the left rear wheel hydraulic circuit bleeder valve tightened securely, after all air purged from the left rear hydraulic circuit, install a proper box-end wrench onto the RIGHT FRONT wheel hydraulic circuit bleeder valve.
15. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
16. With the right front wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the right front hydraulic circuit, install a proper box-end wrench onto the LEFT FRONT wheel hydraulic circuit bleeder valve.
17. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
18. After completing the final wheel hydraulic circuit bleeding procedure, ensure that each of the 4 wheel hydraulic circuit bleeder valves are properly tightened.
19. Fill the brake master cylinder reservoir to the maximum-fill level with GM approved brake fluid from a clean, sealed brake fluid container. Refer to «Master Cylinder Reservoir Filling»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .
20. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
21. If the brake pedal feels spongy, repeat the bleeding procedure again. If the brake pedal still feels spongy after repeating the bleeding procedure, perform the following steps: Inspect the brake system for external leaks. Refer to «Brake System External Leak Inspection»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-external-leak-inspection) . Pressure bleed the hydraulic brake system in order to purge any air that may still be trapped in the system.
22. Turn the ignition key ON, with the engine OFF. Check to see if the brake system warning lamp remains illuminated.
23. If the brake system warning lamp remains illuminated, refer to «Symptoms - Hydraulic Brakes»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__symptoms-hydraulic-brakes) .

Special Tools

1. J-29532: Diaphragm Pressure Bleeder, or equivalent
2. J-35589-A: Brake Pressure Bleeder Adapter

1. Place a clean shop cloth beneath the brake master cylinder to prevent brake fluid spills.
2. With the ignition OFF and the brakes cool, apply the brakes 3-5 times, or until the brake pedal effort increases significantly, in order to deplete the brake booster power reserve.
3. If you have performed a brake master cylinder bench bleeding on this vehicle, or if you disconnected the brake pipes from the master cylinder, you must perform the following steps: Ensure that the brake master cylinder reservoir is full to the maximum-fill level. If necessary add Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container. If removal of the reservoir cap and diaphragm is necessary, clean the outside of the reservoir on and around the cap prior to removal. With the rear brake pipe installed securely to the master cylinder, loosen and separate the front brake pipe from the front port of the brake master cylinder. Allow a small amount of brake fluid to gravity bleed from the open port of the master cylinder. Reconnect the brake pipe to the master cylinder port and tighten securely. Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal. Loosen the same brake pipe to purge air from the open port of the master cylinder. Tighten the brake pipe, then have the assistant slowly release the brake pedal. Wait 15 seconds, then repeat steps 3.3-3.7 until all air is purged from the same port of the master cylinder. With the front brake pipe installed securely to the master cylinder, after all air has been purged from the front port of the master cylinder, loosen and separate the rear brake pipe from the master cylinder, then repeat steps 3.3-3.8. After completing the final master cylinder port bleeding procedure, ensure that both of the brake pipe-to-master cylinder fittings are properly tightened.
4. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container. Clean the outside of the reservoir on and around the reservoir cap prior to removing the cap and diaphragm.
5. Install the J-35589-A: Brake Pressure Bleeder Adapter to the brake master cylinder reservoir.
6. Check the brake fluid level in the J-29532: Diaphragm Pressure Bleeder, or equivalent. Add Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container as necessary to bring the level to approximately the half-full point.
7. Connect the J-29532: Diaphragm Pressure Bleeder, or equivalent, to the J-35589-A: Brake Pressure Bleeder Adapter.
8. Charge the J-29532: Diaphragm Pressure Bleeder, or equivalent, air tank to 175-205 kPa (25-30 psi).
9. Open the J-29532: Diaphragm Pressure Bleeder, or equivalent, fluid tank valve to allow pressurized brake fluid to enter the brake system.
10. Wait approximately 30 seconds, then inspect the entire hydraulic brake system in order to ensure that there are no existing external brake fluid leaks. Any brake fluid leaks identified require repair prior to completing this procedure.
11. Install a proper box-end wrench onto the RIGHT REAR wheel hydraulic circuit bleeder valve.
12. Install a transparent hose over the end of the bleeder valve.
13. Submerge the open end of the transparent hose into a transparent container partially filled with Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
14. Loosen the bleeder valve to purge air from the wheel hydraulic circuit. Allow fluid to flow until air bubbles stop flowing from the bleeder, then tighten the bleeder valve.
15. With the right rear wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the right rear hydraulic circuit, install a proper box-end wrench onto the LEFT REAR wheel hydraulic circuit bleeder valve.
16. Install a transparent hose over the end of the bleeder valve, then repeat steps 13-14.
17. With the left rear wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the left rear hydraulic circuit, install a proper box-end wrench onto the RIGHT FRONT wheel hydraulic circuit bleeder valve.
18. Install a transparent hose over the end of the bleeder valve, then repeat steps 13-14.
19. With the right front wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the right front hydraulic circuit, install a proper box-end wrench onto the LEFT FRONT wheel hydraulic circuit bleeder valve.
20. Install a transparent hose over the end of the bleeder valve, then repeat steps 13-14.
21. After completing the final wheel hydraulic circuit bleeding procedure, ensure that each of the 4 wheel hydraulic circuit bleeder valves are properly tightened.
22. Close the J-29532: Diaphragm Pressure Bleeder, or equivalent, fluid tank valve, then disconnect the J-29532: Diaphragm Pressure Bleeder, or equivalent, from the J-35589-A: Brake Pressure Bleeder Adapter.
23. Remove the J-35589-A: Brake Pressure Bleeder Adapter from the brake master cylinder reservoir.
24. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
25. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
26. If the brake pedal feels spongy perform the following steps: Inspect the brake system for external leaks. Refer to «Brake System External Leak Inspection»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-external-leak-inspection) . Using a scan tool, perform the antilock brake system automated bleeding procedure to remove any air that may have been trapped in the brake pressure modulator valve (BPMV). Refer to the following procedures, as appropriate: «Antilock Brake System Automated Bleed»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-hybrid-hp2-with-electronic-brake-distribution-vehicle-stability-system__antilock-brake-system-automated-bleed) for Two-mode Hybrid vehicles «Antilock Brake System Automated Bleed»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-non-hybrid-less-than-3900-kg-8600-lb-gvw-with-ebd-vses__antilock-brake-system-automated-bleed) for non-hybrid vehicles less than 3900 kg (8600 lb) GVW «Antilock Brake System Automated Bleed»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-non-hybrid-greater-thanequal-to-3900-kg-8600-lb-gvw-with-tcs-ves__antilock-brake-system-automated-bleed) for non-hybrid vehicles greater than/equal to 3900 kg (8600 lb) GVW
27. Turn the ignition key ON, with the engine OFF. Check to see if the brake system warning lamp remains illuminated.
28. If the brake system warning lamp remains illuminated, refer to «Symptoms - Hydraulic Brakes»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__symptoms-hydraulic-brakes) .

1. Inspect the brake fluid for the following conditions, indicating brake fluid contamination: Fluid separation, indicating two types of fluid are present; a substance other than the recommended brake fluid has been introduced into the brake hydraulic system Swirled appearance - oil-based substance Layered appearance - silicone-based substance Fluid discoloration, indicating the presence of moisture or particles that have been introduced into the brake hydraulic system Cloudy appearance - moisture Dark appearance/suspended particles in fluid - dirt, rust, corrosion, brake dust
2. Inspect the master cylinder reservoir cap diaphragm and the reservoir-to-master cylinder grommets for swelling, indicating brake fluid contamination.
3. If the brake fluid WAS contaminated with an oil-based or a silicone-based substance, indicated by fluid separation and/or a swollen master cylinder reservoir cap diaphragm and/or swollen reservoir-to-master cylinder grommets, perform the following: Remove ALL of the following components listed from the vehicle. Each component contains internal rubber seals/linings which have been contaminated by the contaminated brake fluid in the brake hydraulic system. Refer to the procedures indicated as applicable: «Master Cylinder Replacement (JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Master Cylinder Replacement (JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Master Cylinder Replacement (Two-mode Hybrid)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Hose Replacement (JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Hose Replacement (JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Rear Brake Hose Replacement (JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Rear Brake Hose Replacement (Frame to Rear Axle JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Rear Brake Hose Replacement (Frame to Rear Axle JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Rear Brake Hose Replacement (JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Caliper Replacement (2500 Series)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#disc-brake-system__front-brake-caliper-replacement-2500-series) «Front Brake Caliper Replacement (1500 Series)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#disc-brake-system__front-brake-caliper-replacement-1500-series) «Rear Brake Caliper Replacement (2500 Series)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#disc-brake-system__rear-brake-caliper-replacement-2500-series) «Rear Brake Caliper Replacement (1500 Series)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#disc-brake-system__rear-brake-caliper-replacement-1500-series) «Brake Pressure Modulator Valve Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-hybrid-hp2-with-electronic-brake-distribution-vehicle-stability-system) Two-mode Hybrid «Brake Pressure Modulator Valve Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-non-hybrid-less-than-3900-kg-8600-lb-gvw-with-ebd-vses) Non-Hybrid Less than 3900 kg (8600 lb) GVW «Brake Pressure Modulator Valve Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-non-hybrid-greater-thanequal-to-3900-kg-8600-lb-gvw-with-tcs-ves) Non-Hybrid Greater than/Equal to 3900 kg (8600 lb) GVW Clean out all the hydraulic brake pipes using denatured alcohol, or equivalent. Dry the brake pipes using non-lubricated, filtered air. Repair or replace ALL of the following components listed and install them to the vehicle. Each component contains internal rubber seals/linings which have been contaminated by the contaminated brake fluid in the brake hydraulic system. Refer to the procedures indicated as applicable: «Master Cylinder Replacement (JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Master Cylinder Replacement (JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Master Cylinder Replacement (Two-mode Hybrid)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) ; also perform the following: Clean the brake master cylinder reservoir using denatured alcohol, or equivalent, then dry the reservoir using non-lubricated, filtered air. Inspect the reservoir for cracks and/or damage and replace if necessary. Refer to «Master Cylinder Reservoir Replacement (Two-mode Hybrid)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Master Cylinder Reservoir Replacement (JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Master Cylinder Reservoir Replacement (JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) . Replace the brake master cylinder reservoir cap diaphragm. «Front Brake Hose Replacement (JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Hose Replacement (JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Rear Brake Hose Replacement (JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Rear Brake Hose Replacement (Frame to Rear Axle JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Rear Brake Hose Replacement (Frame to Rear Axle JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Rear Brake Hose Replacement (JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Caliper Overhaul (2500 Series)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#disc-brake-system__front-brake-caliper-overhaul-2500-series) or «Front Brake Caliper Replacement (2500 Series)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#disc-brake-system__front-brake-caliper-replacement-2500-series) «Front Brake Caliper Replacement (1500 Series)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#disc-brake-system__front-brake-caliper-replacement-1500-series) «Rear Brake Caliper Overhaul (2500 Series)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#disc-brake-system__rear-brake-caliper-overhaul-2500-series) or «Rear Brake Caliper Replacement (2500 Series)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#disc-brake-system__rear-brake-caliper-replacement-2500-series) «Rear Brake Caliper Replacement (1500 Series)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#disc-brake-system__rear-brake-caliper-replacement-1500-series) «Brake Pressure Modulator Valve Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-hybrid-hp2-with-electronic-brake-distribution-vehicle-stability-system) Two-mode Hybrid «Brake Pressure Modulator Valve Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-non-hybrid-less-than-3900-kg-8600-lb-gvw-with-ebd-vses) Non-Hybrid Less than 3900 kg (8600 lb) GVW «Brake Pressure Modulator Valve Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-non-hybrid-greater-thanequal-to-3900-kg-8600-lb-gvw-with-tcs-ves) Non-Hybrid Greater than/Equal to 3900 kg (8600 lb) GVW
4. If the brake fluid was NOT contaminated with an oil-based or a silicone-based substance, but WAS contaminated with water or dirt, rust, corrosion, and/or brake dust, replace the brake master cylinder reservoir cap diaphragm. The diaphragm may have allowed the moisture or particles to enter the hydraulic system.
5. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11®, GM P/N 12377967 (Canada P/N 992667) or equivalent, DOT-3 brake fluid from a clean, sealed brake fluid container.
6. Pressure bleed the hydraulic brake system. Begin the procedure with the pressure bleeder reservoir filled to the maximum-fill level with the correct brake fluid as indicated. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .

1. Place the ignition switch in the OFF position.
2. Apply and release the brake pedal several times until the brake pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.
3. Disconnect the electrical connector and remove the power brake booster vacuum sensor and vacuum hose and position aside.
4. Remove the brake master cylinder nuts (1).
5. Without disconnecting the brake pipe fittings from the master cylinder, remove the brake master cylinder and support with heavy mechanics wire or equivalent.
6. Inspect the O-ring seal on the master cylinder body for damage and replace, if necessary.
7. Remove the brake booster pushrod retainer bolt (1).
8. Remove the brake booster pushrod retainer (1).
9. Disconnect the electrical connector and remove the stoplamp switch (1).
10. Disconnect the brake booster pushrod from the brake pedal pin.
11. Remove the power vacuum brake booster nuts (1).
12. Remove the power vacuum brake booster.
13. Remove and discard the power vacuum brake booster gasket.

1. Install a new power vacuum brake booster gasket.
2. Install the power vacuum brake booster.
3. Install the power vacuum brake booster nuts (1) and tighten to 33 N.m (24 lb ft).
4. Connect the brake booster pushrod to the brake pedal pin.
5. Install the stoplamp switch (1).
6. Connect the stoplamp switch electrical connector.
7. Install the brake booster pushrod retainer (1).
8. Install the brake booster pushrod retainer bolt (1) and tighten to 10 N.m (89 lb in).
9. Install the O-ring seal on the master cylinder body, if removed.
10. Position the master cylinder to the power vacuum brake booster.
11. Install the brake master cylinder nuts (1) and tighten to 33 N.m (24 lb ft).
12. Install the power brake booster vacuum sensor and vacuum hose.
13. Connect the power brake booster vacuum sensor electrical connector.

1. Turn the ignition switch to the OFF position.
2. Apply and release the brake pedal several times until the brake pedal becomes firm to depete the power vacuum brake booster vacuum reserve.
3. Remove the upper intake manifold sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical/#engine-mechanical-53l-60l-62l-repair-instructions-on-vehicle) .
4. Disconnect the electrical connector from the vacuum sensor.
5. Remove the vacuum sensor with check valve and hose assembly from the power vacuum brake booster.
6. Release the clamp and remove the vacuum brake booster check valve and hose assembly (1).

1. Install the vacuum brake booster check valve and hose assembly (1) and secure the clamp.
2. Install the vacuum sensor with check valve and hose assembly to the power vacuum brake booster.
3. Connect the electrical connector to the vacuum sensor.
4. Install the upper intake manifold sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical/#engine-mechanical-53l-60l-62l-repair-instructions-on-vehicle) .

1. Turn the ignition switch to the OFF position.
2. Apply and release the brake pedal several times until the brake pedal becomes firm to delete the power vacuum brake booster vacuum reserve.
3. Disconnect the electrical connector from the vacuum sensor.
4. Remove the vacuum sensor with check valve and hose assembly from the power vacuum brake booster.
5. Release the clamp and remove the vacuum sensor from the vacuum hose.

1. Install the vacuum sensor with check valve and hose assembly to the power vacuum brake booster.
2. Install the vacuum sensor to the vacuum hose and secure the clamp.
3. Connect the electrical connector to the vacuum sensor.

Scheme 15

1. Turn the ignition to OFF, without pausing at ACCESSORY, and without applying the brake pedal. Remove the ignition key.
2. Wait approximately 1 3 minutes until the brake modulator and HPA pressure relief is complete.
3. Disconnect the brake master cylinder (BMC) primary piston position sensor electrical connector.
4. Remove the 2 BMC primary piston position sensor screws (1).
5. Remove the primary piston position sensor (2). Tilt the rear of the position sensor downward and remove the sensor.

1. Install the BMC primary piston position sensor (2).
2. Install the 2 primary piston position sensor screws (1) and tighten to 10 N.m (89 lb in).
3. Connect the primary piston position sensor electrical connector.
4. Inspect the battery state of charge. Refer to «Battery Inspection/Test»(/cadillac/escalade/gmt900-2006-2014/remont/charging-system/#battery-charging-system-and-starting-system) .
5. If necessary, connect a battery charger to the 12V battery. Refer to «Battery Charging»(/cadillac/escalade/gmt900-2006-2014/remont/charging-system/#battery-charging-system-and-starting-system) .
6. Install a scan tool to the vehicle.
7. Turn the ignition ON with the engine OFF.
8. Using the scan tool, perform the following steps: Select Diagnostics Select the appropriate vehicle information Select Chassis Select Electronic Brake Control Module (EBCM) Select Module Setup Select BMC Primary Piston Position Relearn and follow the instructions on the scan tool

Power Brake Booster Replacement

Checking and Adding Fluid

For information on checking and adding fluid to the hydraulic booster system, refer to Checking and Adding Power Steering Fluid (Without Hydroboost) or Checking and Adding Power Steering Fluid (With Hydroboost) .

Bleeding the Hydraulic Booster System

Refer to Power Steering System Bleeding .

Flushing the Hydraulic Booster System

Refer to Power Steering System Flushing .

1. Apply the park brake and block the wheels.
2. Disconnect the inlet hose, the steering gear, and the return hoses from the booster assembly.
3. Remove the master cylinder to hydraulic booster nuts and set the master cylinder aside in the engine compartment.
4. Remove the stop lamp switch. Refer to «Stop Lamp Switch Replacement (With Adjustable Pedals)»(/cadillac/escalade/gmt900-2006-2014/remont/exterior-lights/#lighting-system) or «Stop Lamp Switch Replacement (Without Adjustable Pedals)»(/cadillac/escalade/gmt900-2006-2014/remont/exterior-lights/#lighting-system) .
5. Remove the 4 booster to bulkhead nuts.
6. Remove the booster assembly.
7. Remove the gasket.

1. Install the gasket.
2. Install the booster assembly.
3. Install the 4 booster to bulkhead nuts and tighten to 33 N.m (24 lb ft).
4. Install the stop lamp switch. Refer to «Stop Lamp Switch Replacement (With Adjustable Pedals)»(/cadillac/escalade/gmt900-2006-2014/remont/exterior-lights/#lighting-system) or «Stop Lamp Switch Replacement (Without Adjustable Pedals)»(/cadillac/escalade/gmt900-2006-2014/remont/exterior-lights/#lighting-system) .
5. Install the master cylinder to the brake booster and tighten to 33 N.m (24 lb ft).
6. Connect the return hose, the steering gear, and the inlet hoses.
7. Bleed the hydraulic booster system. Refer to «Power Steering System Bleeding»(/cadillac/escalade/gmt900-2006-2014/remont/electronic-steering/#power-steering-system) .
8. Release the park brake and unblock the wheels.

J 26889 Accumulator Piston Compressor. See Special Tools .

1. Apply the park brake and block the wheels.
2. Depress brake pedal at least 10 times in order to relieve pressure in the accumulator.
3. Remove the master cylinder from the hydraulic booster. Refer to «Master Cylinder Replacement (JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Master Cylinder Replacement (JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Master Cylinder Replacement (Two-mode Hybrid)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
4. Place the J 26889 over the end of the accumulator. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
5. Install the nut on the stud.
6. Depress the accumulator with a C-clamp. If the accumulator does not move with moderate pressure, remove the C-clamp and depress the brake pedal ten times in order to relieve pressure in the accumulator.
7. Rotate the retaining ring (2) until either end of the ring is under the access hole (1).
8. Depress and hold the retaining ring with a small tool inserted into the access hole (1).
9. Remove the accumulator retainer ring (1) using a small hook shaped tool.
10. Release the C-clamp.
11. Remove the nut from the stud.
12. Remove the J 26889 . See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
13. Remove the accumulator (2) and the O-ring seal (3).

1. Lubricate all of the seals and the metal friction points with power steering fluid.
2. Install the accumulator (2) and the O-ring seal (3).
3. Place the J 26889 over the end of the accumulator. See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
4. Install the nut on the stud.
5. Depress the accumulator with a C-clamp.
6. Install the accumulator retainer ring (1).
7. Release the C-clamp.
8. Remove the nut from the stud.
9. Remove the J 26889 . See «Special Tools»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
10. Install the master cylinder to the hydraulic booster. Refer to «Master Cylinder Replacement (JD9)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Master Cylinder Replacement (JH6)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Master Cylinder Replacement (Two-mode Hybrid)»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
11. Release the park brake and unblock the wheels.

1. Turn the ignition to OFF, without pausing at ACCESSORY, and remove the ignition key.
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
3. Clean any dirt and debris from the brake modulator assembly and the HPA.
4. Loosen the manual pressure relief valve (1) 1/4 turn counterclockwise.
5. Seat, but do not tighten, the manual pressure relief valve.
6. Without disconnecting the brake pipes and hoses, remove the brake pressure modulator assembly bracket. Refer to «Brake Pressure Modulator Valve Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-hybrid-hp2-with-electronic-brake-distribution-vehicle-stability-system) .
7. Remove the HPA (1).
8. Remove and discard the HPA O-ring seal (1).
9. Remove any debris from the O-ring seal groove in the brake modulator assembly with a clean, lint-free shop cloth.
10. If replacing the HPA, properly render inert and dispose of the HPA. Refer to «Power Brake Booster Pump Fluid Accumulator Disposal»(/cadillac/escalade/gmt900-2006-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .

1. Lubricate a new O-ring seal (1) with Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
2. Install the O-ring seal to the HPA. Ensure the seal is fully seated in the groove of the HPA and is not twisted.
3. Install the HPA (1) to the brake modulator assembly. Tighten: Tighten the HPA to 30 N.m (22 lb ft).
4. Install the brake modulator assembly bracket and remove the support. Refer to «Brake Pressure Modulator Valve Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-hybrid-hp2-with-electronic-brake-distribution-vehicle-stability-system) .
5. Tighten the brake modulator manual pressure relief valve (1). Tighten: Tighten the valve to 40 N.m (30 lb ft).
6. Perform the «Antilock Brake System Automated Bleed»(/cadillac/escalade/gmt900-2006-2014/remont/anti-locktraction-control/#antilock-brake-system-hybrid-hp2-with-electronic-brake-distribution-vehicle-stability-system__antilock-brake-system-automated-bleed) . Follow the procedure completely to ensure the learn procedure for the pressure and travel sensors has occurred.

Scheme 16

System Component Description

The brake assist system consists of the following

System Operation

Brake system input force is multiplied by the brake pedal and transferred by the pedal pushrod to the hydraulic brake master cylinder. Effort required to apply the brake system is reduced by the vacuum brake booster.

Active Brake Booster

Incorporated into the vacuum brake booster, is an electric solenoid actuator. This actuator can be used to apply the brake booster and thus the master cylinder as commanded by the electronic brake control module (EBCM). During stability events, the EBCM can command the solenoid actuator in the brake booster to apply the booster. This quickly provides a large volume of pressurized brake fluid to the brake pressure modulator valve (BPMV). The BPMV will then control the flow of fluid to the brake corners to obtain the appropriate response for the vehicle.

Scheme 17

The brake assist system consists of the following

The hydraulic brake boost system uses fluid from the power steering pump (8) through the hydraulic boost inlet hose (3) and to the brake booster assembly (4). In addition to supplying the brake system with fluid for increased apply, the power steering pump is also connected to the power steering gear (6) and cooler (7).

The steering pump (8) is a continuous flow device supplying approximately 3 GPM at 1000 RPM, at the pump shaft. The fluid flows through the booster spool valve, then the return hose (5), and then to the steering gear (6). Pressure is produced by applying the brake pedal, resulting in the spool valve being actuated, internal to the hydraulic brake booster. The spool valve produces a marginal restriction that causes pressure in the booster (4) to rise and forces the power piston and therefore the output rod forward to generate force and motion at the master cylinder (1). The brake corners are actuated by the fluid impulse generated by the master cylinder (1). Internal blow by, or pressure relief, is directed to the low pressure return hose (2) back to the power steering pump (8).

Scheme 18

The hydraulic brake system consists of the following

The brake assist system consists of the following

When the ignition is placed in START or a remote function actuation (RFA) commands remote START, the brake modulator assembly activates and pressurizes brake fluid for use at the wheel apply circuits as needed.

The brake modulator assembly incorporates a motor driven pump which is activated as required to draw brake fluid directly from the master cylinder reservoir, lowering the brake fluid level in the reservoir into the pressurized, or operating, range. The pump pressurizes and delivers the brake fluid to the high pressure accumulator (HPA) to store for use as necessary. Sensor data of HPA fluid pressure is used by the modulator to operate the pump to maintain the pressure of the brake fluid at the HPA within operating range. Working pressure of the HPA stored fluid is 140-180 bar (2030-2610 psi). Peak allowed pressure is 200 bar (2900 psi). Pressure relief is vented back to the master cylinder reservoir.

Brake system mechanical input force from the driver is multiplied by the brake pedal and transferred by the pedal pushrod to the hydraulic brake master cylinder. This mechanical force is converted into hydraulic pressure by the primary piston of the master cylinder. The pressurized brake fluid from the primary piston is delivered to the brake modulator assembly and is directed within the modulator to the brake pedal feel simulator.

To allow operation of the pedal feel simulator, the brake modulator assembly energizes and then closes the normally open (NO) valve to direct brake fluid only to the pedal feel simulator. The brake modulator also energizes and opens a normally closed (NC) valve to allow brake fluid to escape from the backside of the brake pedal feel simulator to the master cylinder reservoir, allowing the simulator piston to move. The pedal feel simulator incorporates a spring which causes increasing brake pedal effort and feedback through the master cylinder, providing brake pedal feel to the driver.

The brake modulator assembly uses sensor data of the brake pedal and pushrod travel and the master cylinder input fluid pressure to determine the amount of braking performance requested by the driver.

Based on the amount of braking action requested by the driver and sensor data inputs of fluid pressure throughout the brake modulator assembly passageways, the modulator uses a boost valve to continuously provide the optimal fluid pressure for use by the wheel apply circuits. The modulator assembly uses the boost valve to both build and relieve pressure within the wheel apply circuits. The boost valve meters the flow of pressurized brake fluid from the HPA to build pressure and relieves pressure as needed by venting fluid through the energized, and open, NC valve to the master cylinder reservoir. The brake modulator assembly also controls various valves in a way similar to a traditional brake modulator, to blend and modulate delivery of brake fluid to the wheel apply circuits, to achieve optimal balance and brake system output performance. The brake modulator delivers brake fluid to the wheel apply circuits as follows

1. Through isolation valves directly to the rear wheel apply circuits
2. Through isolation valves directly to the secondary pistons of the master cylinder
3. The secondary pistons of the master cylinder then delivers pressurized brake fluid directly to the front wheel apply circuits

Pressurized brake fluid is delivered to the wheel apply hydraulic components through the brake pipes and flexible hoses. The wheel apply components then convert the hydraulic pressure back into mechanical force which presses the brake linings against rotating brake system components to slow the vehicle through friction braking.

When the ignition is turned to OFF, without pausing at ACCESSORY, and the brake pedal is not applied, the system will deactivate and depressurize. As the system begins to depressurize, brake fluid will discharge from the HPA and vent back into the master cylinder reservoir. This will cause the brake fluid level in the master cylinder reservoir to rise to the depressurized or system OFF range. The system may take up to 3 minutes to fully depressurize.

If the ignition is turned to ACCESSORY, the system will remain active and pressurized. If the brake pedal is applied before the system has fully depressurized, the brake modulator will maintain the pressure available at the moment of the brake apply until the brake pedal is released. This will increase the amount of time required for the system to depressurize when the ignition is turned to OFF.

The brake modulator assembly also provides a means for manual relief of system pressure through a set-screw. The manual relief of system pressure must be used only if necessary and after the system has powered down.

The brake modulator assembly and the powertrain and hybrid system controllers are in constant communication with each other. Each system is monitoring various system, sensor data, and driver inputs. Working together, a determination is made as to when the most appropriate opportunity for regenerative braking will occur. The brake modulator will request from the powertrain and hybrid controllers the amount of torque braking that is available from the powertrain to be delivered through the primary drive axle. If the powertrain and hybrid controllers in conjunction with the brake modulator have determined to perform a regenerative braking event, the brake modulator will request a specific amount of regenerative or torque braking to be provided from the powertrain.

Simultaneously, the brake modulator continuously evaluates and provides the correct blend of friction braking from the non-primary drive axle, and provides the correct blend of regenerative or torque braking and friction braking from the primary drive axle to provide the most efficient amount of regenerative braking and charging for the needs of the powertrain. All the while, providing optimal braking balance and providing the correct blend and amount of overall vehicle braking action requested by the driver through a brake pedal apply.

Brake system mechanical input force from the driver is multiplied by the brake pedal and transferred by the brake pedal pushrod to the hydraulic brake master cylinder. This mechanical force is converted into hydraulic pressure by the primary piston of the master cylinder.

The pressurized brake fluid from the primary piston is delivered to the brake modulator assembly and is directed within the brake modulator to the wheel apply passageways, rather than to the pedal simulator.

Since the modulator is not energizing the normally open (NO) valve to cause it to close and direct pressurized fluid only to the pedal simulator, the NO valve is open and directing fluid to both the pedal simulator and the wheel apply circuit passageways. To prevent any loss of pressure through the pedal simulator, or through the boost valve, the normally closed (NC) valve is closed since it is not energized by the modulator. Since the NC valve is closed, no fluid can escape from the backside of the simulator, thus preventing any movement of the piston within the pedal simulator and any subsequent loss of pressure. The same is true with the boost valve, since the NC valve is closed, no fluid can escape from the pressure relief side of the boost valve, thus preventing loss of pressure. The pressurized fluid is now delivered through the wheel apply circuit passageways within the modulator as follows

1. Through de-energized, open isolation valves directly to the rear wheel apply circuits
2. Through de-energized, open isolation valves directly to the secondary pistons of the master cylinder
3. The secondary pistons of the master cylinder then deliver pressurized brake fluid directly to the front wheel apply circuits

If a hydraulic failure occurs in the boost circuit of the modulator during further pedal apply, the system will operate as follows

The mechanical input force is applied further as the primary piston of the master cylinder directly contacts the secondary pistons, which then convert the mechanical force into hydraulic pressure. The pressurized brake fluid from the secondary pistons is delivered directly to the front wheel apply circuits.

Brake Warning Indicator

The instrument panel cluster (IPC) illuminates the Red Brake Warning indicator when one or more of the following occurs.

1. The body control module (BCM) detects that the park brake is engaged.
2. The IPC detects a low brake fluid condition. The IPC receives a low brake fluid signal from the low brake fluid switch in the master cylinder reservoir requesting illumination.
3. The electronic brake control module (EBCM) detects an ABS malfunction which disables dynamic rear proportioning (DRP). The IPC receives a serial data message from the EBCM requesting illumination.
4. The IPC performs the bulb check at the start of each ignition cycle. The Red Brake Warning indicator illuminates for approximately 3 seconds before turning OFF.
5. The IPC detects a loss of serial data communications with the EBCM.

The hydraulic brake system consists of the following

Mechanical force is converted into hydraulic pressure by the master cylinder, regulated to meet braking system demands by the pressure balance control system, and delivered to the hydraulic brake wheel circuits by the pipes and flexible hoses. The wheel apply components then convert the hydraulic pressure back into mechanical force which presses linings against rotating brake system components.

Illustrations Tool Number/Description J 26889 Accumulator Piston Compressor J 28662 Brake Pedal Effort Gauge J 29532 Diaphragm Pressure Bleeder J 35589-A Brake Pressure Bleeder Adapter J 45405 Brake Pipe Flaring Tool

Scheme 19

Scheme 20

Scheme 21

Scheme 22

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Component Connector End Views
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Steering Wheel Position Sensor Replacement
• Checking Aftermarket Accessories
• Parking Brake Indicator Switch Replacement
• Park Brake System Diagnosis
• Symptoms - Suspension General Diagnosis
• Symptoms - Power Steering System
• Brake Pad Inspection
• Front Disc Brake Pads Replacement (1500 Series)
• Front Disc Brake Pads Replacement (2500 Series)
• Rear Disc Brake Pads Replacement (2500 Series)
• Rear Disc Brake Pads Replacement (1500 Series)
• Front Brake Caliper Replacement (2500 Series)
• Front Brake Caliper Replacement (1500 Series)
• Rear Brake Caliper Replacement (2500 Series)
• Rear Brake Caliper Replacement (1500 Series)
• Front Disc Brake Mounting and Hardware Inspection
• Rear Disc Brake Mounting and Hardware Inspection
• Front Brake Caliper Bracket Replacement (1500 Series)
• Front Brake Caliper Bracket Replacement (2500 Series)
• Rear Brake Caliper Bracket Replacement (1500 Series)
• Rear Brake Caliper Bracket Replacement (2500 Series)
• Front Brake Caliper Hardware Replacement (2500 Series)
• Front Brake Caliper Hardware Replacement (1500 Series)
• Rear Brake Caliper Hardware Replacement (2500 Series)
• Rear Brake Caliper Hardware Replacement (1500 Series)
• Front Brake Caliper Overhaul (2500 Series)
• Rear Brake Caliper Overhaul (2500 Series)
• Wheel Drive Shaft Outer Joint and Boot Replacement
• Rear Axle Shaft Seal and/or Bearing Replacement
• Front Wheel Hub, Bearing, and Seal Replacement (2500)
• Front Brake Shield Replacement (1500 Series)
• Front Brake Shield Replacement (2500 Series)
• Rear Brake Shield Replacement
• Brake Rotor Thickness Measurement
• Brake Rotor Thickness Variation Measurement
• Brake Rotor Surface and Wear Inspection
• Brake Rotor Refinishing
• Front Brake Rotor Replacement (2500 Series)
• Front Brake Rotor Replacement (1500 Series)
• Rear Brake Rotor Replacement (1500 Series)
• Rear Brake Rotor Replacement (2500 Series)
• Brake Rotor Assembled Lateral Runout Measurement
• Brake Rotor Assembled Lateral Runout Correction
• Brake Pressure Modulator Valve Replacement
• Brake Pressure Modulator Valve Replacement
• Lifting and Jacking the Vehicle
• Tire and Wheel Removal and Installation
• Antilock Brake System Automated Bleed
• Brake Pressure Modulator Valve Replacement
• Battery Charging
• Checking and Adding Power Steering Fluid (Without Hydroboost)
• Brake Fluid Irritant Warning
• Brake Fluid Effects on Paint and Electrical Components Caution
• Fastener Caution
• Brake Dust Warning
• Brake Fluid Warning
• Fluid and Lubricant Recommendations (USA and Canada)
• Antilock Brake System Automated Bleed
• Antilock Brake System Automated Bleed
• Upper Intake Manifold Sight Shield Replacement
• Stop Lamp Switch Replacement (With Adjustable Pedals)
• Safety Glasses Warning
• ABS Description and Operation
• ABS Description and Operation
• ABS Description and Operation
• DTC C0267
• Brake Fluid Loss
• Brake Assist System Diagnosis
• Hydraulic Brake Component Operation Visual Inspection
• Brake Pulsation
• Brake System Noise
• Brake Pedal Excessive Travel (Non-Hybrid)
• Brake Pedal Excessive Travel (Two-mode Hybrid)
• Brake Pedal Excessive Effort
• Brakes Drag
• Brake System Slow Release
• Brakes Self Apply When Turning Steering Wheel
• Symptoms - Hydraulic Brakes
• Brake Pedal Travel Measurement and Inspection (Two-mode Hybrid)
• Brake Pedal Pushrod Inspection
• Master Cylinder Reservoir Filling
• Brake Pipe and Hose Inspection
• Brake System Internal Leak Test (Two-mode Hybrid)
• Brake System Internal Leak Test (Non-Hybrid)
• Brake System Vacuum Source Test
• Power Brake Booster Replacement
• Brake System External Leak Inspection
• Master Cylinder Bench Bleeding