Hydraulic Brake System Cadillac DTS I

Fastener Tightening Specifications

Brake System Specifications

Scheme 25

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Hydraulic Brakes

Begin the hydraulic brake system diagnosis with the Diagnostic System Check - Vehicle . The Diagnostic System Check will provide the following information

1. The identification of the control modules which command the system.
2. The ability of the control modules to communicate through the serial data circuit.
3. The identification of any stored diagnostic trouble codes (DTCs) and their status.

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__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

The ignition is 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. The ABS indicator illuminates.
3. The StabiliTrak indicator illuminates.
4. The Red Brake Warning indicator illuminates.

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/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__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/dts/i-2005-2011/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 1 ohm between the ground circuit terminal B 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 A 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.

Component Testing

1. Ignition OFF, disconnect the harness connector at the brake fluid level switch.
2. Test for infinite resistance between the ground terminal B and the signal terminal A. If less than the specified value, 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»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-fluid-level-indicator-switch-replacement)
2. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for IPC replacement, setup, and programming

Symptoms - Hydraulic Brakes

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) before using the brake indicator symptom tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to «Brake Warning System Description and Operation»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the brake warning system. Refer to «Checking Aftermarket Accessories»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system)
2. «Brake Pulsation»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-pulsation)
3. «Brake System Noise»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-noise)
4. «Braking Action Uneven - Pulls to One Side»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system)
5. «Braking Action Uneven - Front to Rear»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system)
6. «Brake Pedal Excessive Travel»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-pedal-excessive-travel)
7. «Brake Pedal Excessive Effort»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-pedal-excessive-effort)
8. «Brakes Drag»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brakes-drag)
9. «Brake System Slow Release»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-slow-release)
10. «Brake Fluid Loss»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-fluid-loss)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__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/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__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/dts/i-2005-2011/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»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .
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»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .

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 B 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 A 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 B and the signal terminal A. 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»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-fluid-level-indicator-switch-replacement)
2. «Parking Brake Indicator Switch Replacement»(/cadillac/dts/i-2005-2011/remont/parking-brake-system/#parking-brake-system)
3. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM or 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

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.

1. 15: Disc brake rotor thickness variation that exceeds the maximum acceptable level can cause brake pulsation.

1. 19: Disc brake rotor thickness variation that exceeds the maximum acceptable level can cause brake pulsation.

1. 22: Disc brake rotor assembled lateral runout (LRO) that exceeds the maximum acceptable level can lead to thickness variation.

Brake Assist System Diagnosis (Vacuum Assist)

Brake Assist System Diagnosis (Hydraulic Assist)

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/dts/i-2005-2011/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/dts/i-2005-2011/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.

Tools Required

J 28662 Brake Pedal Effort Gage. See Special Tools .

Inspection Procedure

1. 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.
2. Install the J 28662 to the brake pedal. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
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.
9. Compare the brake pedal travel distance with specification. Refer to «Brake System Specifications»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-specifications) .

Brake System Vacuum Source Test

1. Disconnect the engine vacuum hose from the vacuum brake booster check valve.
2. Install a vacuum gage 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 is within the specified normal range, proceed to step 10.
7. If the engine vacuum reading is 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 gage 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.

J 28662 Brake Pedal Effort Gage. See Special Tools .

1. Install the J 28662 to the brake pedal. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) . 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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) . 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

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

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/dts/i-2005-2011/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

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

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/dts/i-2005-2011/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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/dts/i-2005-2011/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 & Hose Inspection

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

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

Note. When adding fluid to the brake master cylinder reservoir, 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. The use of any type of fluid other than the recommended type of brake fluid, may cause contamination which could result in damage to the internal rubber seals and/or rubber linings of hydraulic brake system components.

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

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.

Master Cylinder Reservoir Replacement

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

Removal Procedure

1. Remove the master cylinder from the vehicle. Refer to «Master Cylinder Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .
2. Disconnect the electrical connector from the fluid level sensor.
3. Remove the master cylinder fluid level sensor. Refer to «Brake Fluid Level Indicator Switch Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-fluid-level-indicator-switch-replacement) .
4. Drain the brake fluid from the master cylinder reservoir.
5. Carefully tap back the retaining pins until clear of master cylinder reservoir.
6. Remove the master cylinder reservoir from the master cylinder.
7. Remove the seals from the master cylinder reservoir.

Installation Procedure

1. Inspect the master cylinder reservoir for cracks or deformities. If found, replace the reservoir.
2. Clean the reservoir with clean denatures alcohol or equivalent.
3. Dry the master cylinder reservoir with non-lubricated, filtered air.
4. Lubricate the new seals and the reservoir bayonets with new Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667) or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
5. Install the seals, making sure they are fully seated.
6. Install the reservoir onto the master cylinder by pressing straight down by hand until the pins holes are aligned.
7. Press straight down by hand until pin holes are aligned.
8. Carefully tap in the master cylinder reservoir retaining pins to secure the reservoir.
9. Fill the master cylinder reservoir. Refer to «Master Cylinder Reservoir Filling»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .
10. Install the master cylinder fluid level sensor. Refer to «Brake Fluid Level Indicator Switch Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-fluid-level-indicator-switch-replacement) .
11. Connect the electrical connector to fluid sensor.
12. Install the master cylinder. Refer to «Master Cylinder Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .

Scheme 26

Master Cylinder Bench Bleeding

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

Note. When adding fluid to the brake master cylinder reservoir, 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. The use of any type of fluid other than the recommended type of brake fluid, may cause contamination which could result in damage to the internal rubber seals and/or rubber linings of hydraulic brake system components.

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 Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
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.

Brake Fluid Level Indicator Switch Replacement

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

1. Disconnect the electrical connector (1) from the brake fluid level sensor.
2. Using a needle nose pliers carefully depress the retaining tabs (1) on the end of the brake fluid level sensor and press the sensor through the reservoir to remove.

1. Align the brake fluid level sensor to the master cylinder reservoir.
2. Press the brake fluid level sensor into the master cylinder reservoir.
3. Connect the electrical connector to the brake fluid level sensor.

Scheme 27

J 45405 Pipe Flaring Tool Kit. See Special Tools .

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

Replacement Procedure

1. Inspect the section of brake pipe to be 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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) . 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 IMPORTANT: Ensure that the brake pipe end to be flared is cut at a square, 90 degree angle to the pipe length.
6. Using the pipe cutter included in the J 45405 , carefully cut the brake pipe squarely to the measured length. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
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 ends 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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) . Specification: 6.35 mm (0.250 in) blade for 4.76 mm (3/16 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. IMPORTANT: 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. IMPORTANT: 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
10. Chamfer the inside and outside diameter of the pipe with the de-burring tool included in the J 45405 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
13. Loosen the die clamping screw of the J 45405 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
24. Rotate the hydraulic fluid control valve counterclockwise to the open position to allow the hydraulic forming ram to retract.
25. Loosen the die clamping screw and remove the dies and pipe.
26. If necessary, lightly tap the dies until the die halves separate.
27. Inspect the brake pipe flare for correct shape and diameter (a). Specification: 7.10 mm (0.279 in) +/- 0.18 mm (0.007 in) flare diameter for 4.76 mm (3/16 in) diameter pipe
28. If necessary, using the removed section of pipe as a template, shape the new pipe with a suitable brake pipe bending tool. IMPORTANT: When installing the pipe, maintain a clearance of 19 mm (3/4 in) from all moving or vibrating components.
29. Install the pipe to the vehicle with the appropriate brake pipe unions as required.
30. If previously released, secure the brake pipe to the retainers.
31. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .
32. With the aid of an assistant, inspect the brake pipe flares for leaks by starting the engine and applying the brakes.

Front Brake Hose Replacement

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/dts/i-2005-2011/remont/hoistjack/#general-information__lifting-jacking-the-vehicle) .
2. Remove the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/dts/i-2005-2011/remont/wheel-tire-system/#tires-and-wheels__tire-wheel-removal-installation) .
3. Clean all dirt and foreign material from the brake hose and the brake pipe fittings.
4. Remove the brake pipe fitting from the brake hose.
5. Use a flat-bladed tool in order to remove the brake hose retainer from the brake hose.
6. Remove the brake hose from the brake hose bracket.
7. Remove the brake hose bolt from the brake caliper.
8. Remove the brake hose from the brake caliper.
9. Remove and discard the two copper brake hose gaskets. These gaskets may be stuck to the brake caliper and/or the brake hose end.
10. Plug the inlet port of the brake caliper to prevent brake fluid loss and contamination.
11. Remove the hose bracket bolt from the strut assembly and remove the hose.

1. Remove the plug from the brake caliper inlet port, if necessary.
2. Assemble the brake hose bolt and the NEW copper brake hose gaskets to the brake hose.
3. Install the brake hose to caliper bolt. Tighten: Tighten the brake hose to caliper bolt to 40 N.m (30 lb ft) (JL9). Tighten the brake hose to caliper bolt to 45 N.m (33 lb ft) (J55).
4. Install the brake hose to the brake hose bracket.
5. Install the brake hose retainer to the brake hose.
6. Remove the cap from the exposed brake pipe fitting end.
7. Install the brake pipe fitting to the brake hose. Tighten: Tighten the brake pipe fitting to 15 N.m (11 lb ft).
8. Install the hose bracket and bolt to the strut assembly. Tighten: Tighten the bolt to 17 N.m (13 lb ft).
9. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .
10. Install the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/dts/i-2005-2011/remont/wheel-tire-system/#tires-and-wheels__tire-wheel-removal-installation) .
11. Lower the vehicle.

Rear Brake Hose Replacement

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/dts/i-2005-2011/remont/hoistjack/#general-information__lifting-jacking-the-vehicle) .
2. Remove the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/dts/i-2005-2011/remont/wheel-tire-system/#tires-and-wheels__tire-wheel-removal-installation) .
3. Clean all dirt and foreign material from the brake hose and the brake pipe fittings.
4. Remove the brake pipe fitting from the brake hose.
5. Use a flat-bladed tool in order to remove the brake hose retainer from the brake hose.
6. Remove the brake hose from the brake hose bracket.
7. Remove the brake hose bolt from the brake caliper.
8. Remove the brake hose from the brake caliper.
9. Remove and discard the two copper brake hose gaskets. These gaskets may be stuck to the brake caliper and/or the brake hose end.
10. Plug the brake caliper inlet port to prevent brake fluid loss and contamination.

1. Remove the plug from the inlet port of the brake caliper, if necessary.
2. Assemble the brake hose bolt and the NEW copper brake hose gaskets to the brake hose.
3. Install the brake hose bolt to the brake caliper. Tighten: Tighten the brake hose to caliper bolt to 40 N.m (30 lb ft) (JL9). Tighten the brake hose to caliper bolt to 45 N.m (33 lb ft) (J55).
4. Install the brake hose to the brake hose bracket.
5. Install the brake hose retainer to the brake hose.
6. Remove the cap from the brake pipe fitting end.
7. Install the brake pipe fitting to the brake hose. Tighten: Tighten the brake pipe fitting to 15 N.m (11 lb ft).
8. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .
9. Install the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/dts/i-2005-2011/remont/wheel-tire-system/#tires-and-wheels__tire-wheel-removal-installation) .
10. Lower the vehicle.

Note. When adding fluid to the brake master cylinder reservoir, 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. The use of any type of fluid other than the recommended type of brake fluid, may cause contamination which could result in damage to the internal rubber seals and/or rubber linings of hydraulic brake system components.

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

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 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. 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 Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
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 FRONT 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 front wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the left front hydraulic circuit, install a proper box-end wrench onto the LEFT REAR 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 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.
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 Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
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/dts/i-2005-2011/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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__symptoms-hydraulic-brakes) .

Tools Required

1. J 29532 Diaphragm Type Brake Pressure Bleeder, or equivalent. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
2. J 35589-A Master Cylinder Bleeder Adapter. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .

Note. When adding fluid to the brake master cylinder reservoir, 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. The use of any type of fluid other than the recommended type of brake fluid, may cause contamination which could result in damage to the internal rubber seals and/or rubber linings of hydraulic brake system components.

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

Bleeding Procedure

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 to the brake master cylinder reservoir. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
6. Check the brake fluid level in the J 29532 , or equivalent. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) . 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 , or equivalent, to the J 35589-A . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
8. Charge the J 29532 , or equivalent, air tank to 175-205 kPa (25-30 psi). See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
9. Open the J 29532 , or equivalent, fluid tank valve to allow pressurized brake fluid to enter the brake system. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
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 FRONT 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 front wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the left front hydraulic circuit, install a proper box-end wrench onto the LEFT REAR 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 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
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 , or equivalent, fluid tank valve, then disconnect the J 29532 , or equivalent, from the J 35589-A . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
23. Remove the J 35589-A from the brake master cylinder reservoir. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
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/dts/i-2005-2011/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 «Antilock Brake System Automated Bleed Procedure»(/cadillac/dts/i-2005-2011/remont/anti-locktraction-control/#anti-lock-brake-system-traction-control-system-stability-control-system__antilock-brake-system-automated-bleed-procedure) .
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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__symptoms-hydraulic-brakes) .

Note. When adding fluid to the brake master cylinder reservoir, 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. The use of any type of fluid other than the recommended type of brake fluid, may cause contamination which could result in damage to the internal rubber seals and/or rubber linings of hydraulic brake system components.

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

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: «Master Cylinder Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Hose Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__front-brake-hose-replacement) «Rear Brake Hose Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__rear-brake-hose-replacement) «Front Brake Caliper Replacement (J55)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#disc-brake-system__front-brake-caliper-replacement-j55) «Front Brake Caliper Replacement (JL9)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#disc-brake-system) «Rear Brake Caliper Replacement (J55)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#disc-brake-system) «Rear Brake Caliper Replacement (JL9)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#disc-brake-system) «Brake Pressure Modulator Valve Replacement»(/cadillac/dts/i-2005-2011/remont/anti-locktraction-control/#anti-lock-brake-system-traction-control-system-stability-control-system) 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: «Front Brake Hose Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__front-brake-hose-replacement) «Rear Brake Hose Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__rear-brake-hose-replacement) «Front Brake Caliper Overhaul»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#disc-brake-system__front-brake-caliper-overhaul) or «Front Brake Caliper Replacement (J55)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#disc-brake-system__front-brake-caliper-replacement-j55) «Front Brake Caliper Replacement (JL9)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#disc-brake-system) «Rear Brake Caliper Replacement (J55)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#disc-brake-system) «Rear Brake Caliper Replacement (JL9)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#disc-brake-system) «Brake Pressure Modulator Valve Replacement»(/cadillac/dts/i-2005-2011/remont/anti-locktraction-control/#anti-lock-brake-system-traction-control-system-stability-control-system)
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 U.S. P/N 12377967, GM 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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .

1. Place the vehicle on a flat surface.
2. Block the front wheels.
3. Apply the parking brake.
4. To allow access for the removal of the vacuum brake booster, position the gearshift lever into the lowest gear.
5. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
6. Disconnect the fuel vapor lines in front of the brake booster. For the lines that have the plastic connectors, refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . For the lines that have the metal connectors, refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
7. Remove the master cylinder mounting nuts (3).
8. Disconnect the master cylinder (1) from the brake booster (2).
9. Disconnect the shift control cable from the shaft lever pin and position it out of the way. Refer to «Automatic Transmission Range Selector Cable Replacement - Console»(/cadillac/dts/i-2005-2011/remont/automatic-trans/#how-to-overhaul-the-automatic-transaxle-4t80-e-removal-installation-service-troubleshooting-diagnosis) .
10. Disconnect the vacuum check valve (2) from the vacuum booster.
11. Remove the inlet heater pipe from the bracket at the transmission. Refer to «Heater Pipes Replacement»(/cadillac/dts/i-2005-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
12. Remove the left closeout insulator panel. Refer to «Instrument Panel Insulator Panel Replacement - Left Side»(/cadillac/dts/i-2005-2011/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
13. Remove the left knee bolster. Refer to «Driver Knee Bolster Replacement»(/cadillac/dts/i-2005-2011/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
14. To access the left lower brake pedal to vacuum brake booster mounting nut, remove the steering column mounting nuts. Refer to «Steering Column Replacement»(/cadillac/dts/i-2005-2011/remont/steering-column-switches/#steering-wheel-steering-column) .
15. Lower the steering column and secure it.
16. Remove the vacuum brake booster pushrod retaining clip (2) from the brake pedal clevis pin.
17. Remove the foam spacer (3) from the brake pedal clevis pin.
18. Disconnect the brake booster pushrod from the brake pedal clevis pin.
19. Remove the vacuum brake booster mounting nuts (1) from the brake pedal assembly.
20. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/dts/i-2005-2011/remont/hoistjack/#general-information__lifting-jacking-the-vehicle) .
21. Support the front frame with jack stands.
22. Loosen the left side bolts from the frame to the body. Refer to «Front Frame Replacement (4.6L)»(/cadillac/dts/i-2005-2011/remont/frames-subframes-crossmembers/#frame-and-underbody) .
23. Lower the left side frame 2-3 inches to gain enough clearance to remove the brake booster. Refer to «Front Frame Replacement (4.6L)»(/cadillac/dts/i-2005-2011/remont/frames-subframes-crossmembers/#frame-and-underbody) .
24. Remove the vacuum brake booster from the vehicle.
25. Remove the vacuum brake booster mounting gasket.

1. Install the vacuum brake booster mounting gasket to the booster, if removed previously.
2. Install the vacuum brake booster to the vehicle.
3. Lower the vehicle onto the engine frame. Refer to «Front Frame Replacement (4.6L)»(/cadillac/dts/i-2005-2011/remont/frames-subframes-crossmembers/#frame-and-underbody) .
4. Remove the jack stands.
5. Lower the vehicle.
6. Install the brake pedal assembly to booster stud mounting nuts (1) to the booster studs. Tighten: Tighten the brake pedal assembly to booster stud mounting nuts to 30 N.m (22 lb ft).
7. Apply a small amount of lubricant, GM P/N 12346293 or equivalent to the clevis pin of the brake pedal.
8. Connect the vacuum brake booster pushrod to the brake pedal clevis pin.
9. Install the foam spacer (3) to the brake pedal clevis pin.
10. Install the retainer clip (2) to the brake pedal assembly clevis pin.
11. Install the steering column.
12. Install the steering column mounting attaching nuts. Refer to «Steering Column Replacement»(/cadillac/dts/i-2005-2011/remont/steering-column-switches/#steering-wheel-steering-column) .
13. Install the left knee bolster. Refer to «Driver Knee Bolster Replacement»(/cadillac/dts/i-2005-2011/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
14. Install the left closeout insulator panel. Refer to «Instrument Panel Insulator Panel Replacement - Left Side»(/cadillac/dts/i-2005-2011/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
15. Install the inlet heater pipe. Refer to «Heater Pipes Replacement»(/cadillac/dts/i-2005-2011/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
16. Install the shift control cable to the shift cable bracket. Refer to «Automatic Transmission Range Selector Cable Replacement - Console»(/cadillac/dts/i-2005-2011/remont/automatic-trans/#how-to-overhaul-the-automatic-transaxle-4t80-e-removal-installation-service-troubleshooting-diagnosis) .
17. Position the gearshift lever into park.
18. Install the brake booster vacuum check valve (2) to the vacuum brake booster.
19. Install the master cylinder to the vacuum brake booster. Refer to «Master Cylinder Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .
20. Connect the fuel vapor lines in front of the brake booster. For the lines that have the plastic connectors, refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . For the lines that have the metal connectors, refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
21. Remove the blocks from the front wheels.
22. Release the parking brake.

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-2-of-5) .
2. Disconnect the vacuum hose (2) from vacuum brake booster.
3. Disconnect the vacuum hose (2) from the intake manifold (1).
4. Remove the vacuum brake booster check valve (2) from the vacuum brake booster hose (1).

1. Connect the vacuum hose (2) to the intake manifold (1).
2. Install the vacuum brake booster check valve (2) to the vacuum brake booster hose (1).
3. Connect the vacuum hose (2) to vacuum brake booster.
4. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-2-of-5) .

Power Brake Booster Replacement

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

Note. Hydraulic brake systems use two distinct and incompatible fluids. Power steering fluid is used in the hydraulic brake booster system. Brake fluid is used in the master cylinder and brake pipes. Use extreme care when selecting brake system fluids, or seal damage can result. Refer to General Information to select the correct fluid.

1. Disconnect the battery negative cable.
2. Place the vehicle on a level surface.
3. Block the front wheels.
4. Apply the parking brake.
5. Disconnect the power steering inlet hose. Refer to «Power Steering Return Hose Replacement»(/cadillac/dts/i-2005-2011/remont/manual-power-steering/#power-steering-system) .
6. Disconnect the power steering pressure hose. Refer to «Power Steering Pressure Pipe/Hose Replacement»(/cadillac/dts/i-2005-2011/remont/manual-power-steering/#power-steering-system) .
7. Disconnect the power steering gear to booster hose. Refer to «Power Steering Pressure Pipe/Hose Replacement»(/cadillac/dts/i-2005-2011/remont/manual-power-steering/#power-steering-system) .
8. Remove the master cylinder. Refer to «Master Cylinder Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .
9. Remove the wiring harness bracket (2).
10. Remove the spacer (3) from the booster assembly (4).
11. Remove the left closeout insulator panel. Refer to «Instrument Panel Insulator Panel Replacement - Left Side»(/cadillac/dts/i-2005-2011/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
12. Remove the left knee bolster. Refer to «Driver Knee Bolster Replacement»(/cadillac/dts/i-2005-2011/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
13. Remove the vacuum brake booster retainer clip (2) from the brake pedal clevis pin.
14. Remove the foam spacer (3) from the brake pedal clevis pin.
15. Disconnect the vacuum brake booster push rod from the brake pedal clevis pin.
16. Remove the vacuum brake booster mounting nuts (1) from the brake pedal assembly.
17. Remove the vacuum brake booster assembly.
18. Remove the vacuum brake booster mounting gasket, if gasket replacement is necessary.

1. Install the vacuum brake booster mounting gasket to the booster, if removed previously.
2. Install the vacuum brake booster assembly to the vehicle.
3. Install the brake pedal assembly to booster stud mounting nuts (1). Tighten: Tighten the brake pedal assembly to booster stud mounting nuts to 36 N.m (27 lb ft).
4. Apply a small amount of lubricant, GM P/N 12346293 or equivalent to the clevis pin of the brake pedal.
5. Connect the vacuum brake booster pushrod to the brake pedal assembly pedal clevis pin.
6. Install the foam spacer (3) to the brake pedal assembly clevis pin.
7. Install the retaining clip (2) to the brake pedal assembly clevis pin.
8. Install the left knee bolster. Refer to «Driver Knee Bolster Replacement»(/cadillac/dts/i-2005-2011/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
9. Install the left closeout insulator panel. Refer to «Instrument Panel Insulator Panel Replacement - Left Side»(/cadillac/dts/i-2005-2011/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
10. Install the booster spacer (3).
11. Install the wiring harness bracket (2).
12. Install the master cylinder (1) to the booster assembly (4). Refer to «Master Cylinder Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .
13. Connect the power steering pressure hose. Refer to «Power Steering Pressure Pipe/Hose Replacement»(/cadillac/dts/i-2005-2011/remont/manual-power-steering/#power-steering-system) .
14. Connect the power steering gear to booster hose. Refer to «Power Steering Pressure Pipe/Hose Replacement»(/cadillac/dts/i-2005-2011/remont/manual-power-steering/#power-steering-system) .
15. Connect the power steering inlet hose. Refer to «Power Steering Return Hose Replacement»(/cadillac/dts/i-2005-2011/remont/manual-power-steering/#power-steering-system) .
16. Connect the negative battery cable.
17. Bleed the hydraulic booster system. Refer to «Power Steering System Bleeding»(/cadillac/dts/i-2005-2011/remont/manual-power-steering/#power-steering-system) .
18. Recalibrate the brake position sensor. Refer to «Brake Pedal Position Sensor Calibration»(/cadillac/dts/i-2005-2011/remont/exterior-lights/#lighting-systems) .
19. Remove the blocks from the front wheels.
20. Release the park brake.

J 26889 Accumulator Piston Compressor. See Special Tools .

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

1. Press brake pedal at least ten times to relieve pressure in the accumulator.
2. Remove the master cylinder from the hydraulic brake booster. Refer to «Master Cylinder Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .
3. Place the J 26889 over the end of the accumulator. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
4. Install the nut on the stud.
5. Press the accumulator with a C-clamp. If accumulator does not move with moderate pressure, remove the C-clamp and press brake pedal 10 times to relieve pressure in the accumulator.
6. Rotate retaining ring (2) until either end of the ring is under the access hole (1).
7. Press and hold the retaining ring (2) with a small tool inserted into the access hole (1).
8. Remove the accumulator retainer ring (1) using a small hook shaped tool.
9. Release the C-clamp.
10. Remove the nut from the stud.
11. Remove the J 26889 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
12. Remove the accumulator (2) and O-ring seal (3).

1. Lubricate all seals and metal friction points with power steering fluid.
2. Install the accumulator (2) and O-ring seal (3).
3. Place the J 26889 over the end of the accumulator. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
4. Install the nut on the stud.
5. Press 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/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system__special-tools) .
10. Install the master cylinder to the hydraulic booster. Refer to «Master Cylinder Replacement»(/cadillac/dts/i-2005-2011/remont/mechanical-hydraulic/#hydraulic-brake-system) .

Description & Operation

Note. System does not use a Brake/stop lamp switch. System uses a brake pedal position sensor. This sensor input is used to determine brake application and to turn on brake/stop lamps.

The instrument panel cluster (IPC) illuminates the BRAKE indicator when any of the following occurs

1. The body control module (BCM) detects that the park brake is applied and sends serial data message to illuminate indicator.
2. The IPC detects a low brake fluid condition.
3. The electronic brake control module (EBCM) detects a malfunction with the antilock brake system (ABS). The IPC receives a serial data message from the EBCM requesting illumination.
4. The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 5 seconds.

Check Brake Fluid

The IPC illuminates the CHECK BRAKE FLUID indicator in the driver information center (DIC) and sends a serial data message in order to activate an audible warning when the IPC detects that the brake fluid level is below the normal operating range.

System Component Description

The hydraulic brake system consists of the following

System Operation

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.

The brake assist system consists of the following

Brake system input force from the driver 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 operation of the vacuum brake booster.

When brake system force is applied, vacuum to the rear of the diaphragm(s) is cut off, and air at atmospheric pressure is admitted in its place. The vacuum acts to pull the diaphragm(s) forward, while the atmospheric pressure acts to push from behind. As a result, the amount of effort required by the driver is reduced. When input force is removed, vacuum again replaces atmospheric pressure within the vacuum power brake booster to help return the booster to rest. Return springs maintain the system in a rest position.

If the vehicle is equipped with a vacuum monitoring system, the powertrain control module(s) typically will alter powertrain functions and/or command the vacuum pump ON, if equipped, to provide for the vacuum needs of the brake assist system, as operating conditions warrant.

Special Tools

Illustration Tool Number/ Description J 26889 Accumulator Piston Compressor J 28662 Brake Pedal Effort Gage J 29532 Diaphragm Pressure Bleeder J 35589-A Master Cylinder Bleeder Adapter J 45405 Pipe Flaring Tool Kit

Scheme 28

Scheme 29

Scheme 30

Scheme 31

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
• Checking Aftermarket Accessories
• Parking Brake Indicator Switch Replacement
• Park Brake System Diagnosis (Without J55)
• Park Brake System Diagnosis (J55)
• Diagnostic Starting Point - Suspension General Diagnosis
• Diagnostic Starting Point - Power Steering System (w/o Electro-Hydraulic Steering)
• Brake Pad Inspection
• Front Disc Brake Pads Replacement (JL9)
• Front Disc Brake Pads Replacement (J55)
• Front Brake Caliper Replacement (J55)
• Front Disc Brake Mounting and Hardware Inspection
• Rear Disc Brake Mounting and Hardware Inspection
• Front Brake Caliper Bracket Replacement (J55)
• Front Disc Brake Hardware Replacement (J55)
• Front Brake Caliper Overhaul
• Wheel Drive Shaft Outer Joint and Boot Replacement (FE1/FE3)
• Brake Rotor Thickness Measurement (JL9)
• Brake Rotor Thickness Measurement (J55)
• Brake Rotor Thickness Variation Measurement
• Brake Rotor Surface and Wear Inspection
• Brake Rotor Refinishing
• Front Brake Rotor Replacement (J55)
• Brake Rotor Assembled Lateral Runout Measurement
• Brake Rotor Assembled Lateral Runout Correction
• Brake Pressure Modulator Valve Replacement
• Lifting and Jacking the Vehicle
• Tire and Wheel Removal and Installation
• Diagnostic Starting Point - Engine Controls
• Checking and Adding Power Steering Fluid
• Brake Fluid Irritant Caution
• Brake Fluid Effects on Paint and Electrical Components Notice
• Fastener Notice
• Driver Knee Bolster Replacement
• Steering Column Replacement
• Brake Pedal Position Sensor Calibration
• Antilock Brake System Automated Bleed Procedure
• Air Cleaner Assembly Replacement
• Automatic Transmission Range Selector Cable Replacement - Console
• Heater Pipes Replacement
• Front Frame Replacement (4.6L)
• Fuel Injector Sight Shield Replacement
• General Information
• Battery Disconnect Caution
• ABS Description and Operation
• DTC C0267
• Brake Fluid Loss
• Brake Fluid Level Indicator Switch Replacement
• Brake Pulsation
• Brake System Noise
• Brake Pedal Excessive Travel
• Brake Pedal Excessive Effort
• Brakes Drag
• Brake System Slow Release
• Diagnostic Starting Point - Hydraulic Brakes
• Brake Assist System Diagnosis (Vacuum Assist)
• Brake Assist System Diagnosis (Hydraulic Assist)
• Brake Pedal Pushrod Inspection
• Front Brake Hose Replacement
• Rear Brake Hose Replacement
• Master Cylinder Reservoir Filling
• Hydraulic Brake Component Operation Visual Inspection
• Brake Pipe and Hose Inspection
• Brake System Internal Leak Test
• Brake System Vacuum Source Test
• Power Brake Booster Replacement
• Symptoms - Hydraulic Brakes
• Special Tools
• Brake System Specifications
• Brake System External Leak Inspection
• Fastener Tightening Specifications
• Master Cylinder Bench Bleeding