Hydraulic Brake System Cadillac CTS II

Fastener Tightening Specifications

Brake Component Specifications

Brake System Specifications

Scheme 7

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/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 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.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Brake Fluid Level Indicator Switch Replacement»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
2. «Control Module References»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The brake booster vacuum sensor measures the vacuum in the brake booster assembly. The electronic brake control module (EBCM) supplies a 5 V reference and a low reference circuit to the brake booster vacuum sensor. The vacuum sensor supplies a voltage signal in relation to the pressure in the brake booster to the EBCM. When the vacuum within the system drops, the EBCM turns ON the vacuum pump by providing ground to the vacuum pump relay. The relay activates and supplies voltage to the brake booster pump motor.

Ignition ON

The EBCM detects a vacuum leak.

The brake warning indicator turns ON.

1. A current DTC clears when the diagnostic runs and passes.
2. The EBCM will turn OFF the indicator in the next ignition cycle.

Schematic Reference

Hydraulic Brake Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Brake Assist System Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/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, apply and release the brake pedal several times to ventilate the brake booster.
2. Engine running, the M9 Brake Booster Pump Motor should turn ON for a short time.

1. Ignition OFF, disconnect the harness at the brake booster pump relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground. If the test lamp illuminates, test the control circuit for a short to voltage.
3. Verify that a test lamp illuminates between the B+ circuit terminal 30 and ground. If the test lamp does not illuminate, test the B+, circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+, circuit fuse is open, test or replace the brake booster pump relay.
4. Verify that a test lamp illuminates between the Ignition, circuit terminal 86 and ground. If the test lamp does not illuminate, test the ignition, circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition, circuit fuse is open, test the control circuit terminal 87 for a short to ground.
5. Disconnect the harness connector at the brake booster pump.
6. Test for less than 1 ohms between the brake booster pump ground circuit terminal 2 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
7. Connect the harness connector at the brake booster pump.
8. Connect a 20 A fused jumper wire between the B+, circuit terminal 30 and the control circuit terminal 87. Verify the brake booster pump is activated. If the brake booster pump does not activate, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the brake booster pump.
9. Connect a test lamp between the ignition circuit terminal 86 and the control circuit terminal 85.
10. Command the brake booster pump ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the brake booster pump. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the brake booster pump.
11. If all circuits test normal, test or replace the brake booster pump relay.

Component Testing

Vacuum Pump Motor Test

1. Ignition OFF, disconnect the harness connector at the M9 brake booster pump.
2. Connect a 20 A fused jumper wire between the control circuit terminal 1 and B+.
3. Connect a jumper wire between the ground circuit terminal 2 and ground, verify the M9 brake booster pump activates. If the M9 brake booster pump does not activate, replace the M9 brake booster pump motor.

Relay Test

1. Ignition OFF, disconnect the brake booster pump relay.
2. Test for 60-100 ohms between terminals 85 and 86 of the relay. If not within the specified range, replace the brake booster pump relay.
3. Test for infinite resistance between the following terminals: 30 and 85 30 and 86 30 and 87 If less than the specified value, replace the brake booster pump relay.
4. Install a fused jumper wire between relay terminal 86 and B+. Install a jumper wire between relay terminal 85 and ground.
5. Test for less than 5 ohms between terminals 30 and 87. If greater than the specified value, replace the brake booster pump relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Relay Replacement (Attached to Wire Harness)»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) or «Relay Replacement (Within an Electrical Center)»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
2. «Control Module References»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The brake booster vacuum sensor measures the vacuum in the brake booster assembly. The electronic brake control module (EBCM) supplies a 5 V reference and a low reference circuit to the brake booster vacuum sensor. The vacuum sensor supplies a voltage signal in relation to the pressure in the brake booster to the EBCM.

Ignition ON.

C1100 00

If the vacuum sensor 5 V reference circuit is greater than 4.9 V for more than 100 m/sec.

C1100 01

The EBCM detects a voltage greater than 4.9 V for more than 100 m/sec on the vacuum sensor 5 V reference circuit.

C1100 02

The EBCM detects a voltage less than 0.2 V for more than 100 m/sec on the vacuum sensor 5 V reference circuit.

C1100 08, C1100 09, and C1100 5A

1. The vacuum sensor signal is not plausible.
2. Defective wiring vacuum sensor, or microprocessor feedback may cause erratic pressure sensor fault.

The brake warning indicator turns ON.

1. A current DTC clears when the diagnostic runs and passes.
2. The EBCM will turn OFF the indicator in the next ignition cycle.

Schematic Reference

Hydraulic Brake Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/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 at the brake booster vacuum sensor.
2. Ignition OFF, test for less than 10 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 a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
4. Ignition ON, test for 4.5-5.2 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 voltage. If the circuit tests normal, replace the EBCM.
5. Ignition OFF, disconnect the X1 harness connector at the EBCM.
6. Ignition OFF, test for infinite resistance between the signal circuit terminal 21 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 power brake booster vacuum sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Relay Replacement (Attached to Wire Harness)»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) or «Relay Replacement (Within an Electrical Center)»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
2. «Control Module References»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) monitors the control circuit of the brake booster pump relay. The ECM supplies ground through the pump relay control circuit which then supplies B+ voltage to actuate the brake booster pump. B+ voltage is supplied at all times to the coil side of the pump relay.

P258A, P258C, P258D

Ignition ON.

P258B

1. Engine Running
2. Vacuum pump is activated for greater than 1.6 seconds.

P258A, P258C

The ECM detects an open/high resistance on the relay coil control circuit.

The ECM detects an excessive difference in vacuum levels between the power brake booster and the manifold absolute pressure (MAP).

P258D

The ECM detects a short to voltage on the relay control circuit.

DTC P258A, P258B, P258C, P258D are Type B DTCs.

DTC P258A, P258B, P258C, P258D are Type B DTCs.

Schematic Reference

Hydraulic Brake Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Brake Booster Vacuum Assist Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Verify that a vacuum leak is not present, refer to «Brake System Vacuum Source Test»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-vacuum-source-test)
2. Ignition ON, command the relay ON and OFF with a scan tool. Observe to verify that the vacuum relay and motor turns ON and OFF with each command.

1. Ignition OFF, disconnect the vacuum pump relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground. If the test lamp illuminates, test the control circuit for a short to voltage.
3. Verify that a test lamp illuminates between the B+ circuit terminals listed below and ground. Terminal 30 Terminal 86 If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test or replace the relay.
4. Verify that a test lamp does not illuminate between the control circuit terminal 85 and ground. If the test lamp illuminates, test the control circuit for a short to voltage.
5. Disconnect the harness connector at the vacuum pump.
6. Test for less than 2 ohms between the vacuum pump ground circuit terminal 2 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
7. Connect the harness connector at the vacuum pump.
8. Connect a 20A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the vacuum pump is activated. If the vacuum pump does not activate, test the control circuit for a short ground or an open/high resistance. If the circuit tests normal, test or replace the vacuum pump.
9. Ignition OFF, test for infinite resistance between the control circuit terminal 85 and ground. If less than the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
10. Disconnect the X1 harness connector at the ECM.
11. Test for less than 2 ohms between the control circuit terminal 85 at the relay cavity and terminal 18 at the ECM harness connector. If greater than the specified range, test the control circuit for an open/high resistance.
12. If all circuits test normal, replace the brake booster pump relay. If the DTC resets, replace the power brake booster vacuum pump.

1. Ignition OFF, disconnect the vacuum pump relay.
2. Test for 60-180 ohms between terminals 85 and 86. If the resistance is not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals: 30 and 85 30 and 87 30 and 86 86 and 87 If not the specified value, replace the relay.
4. Install a 30A fused jumper wire between relay terminal 86 and B+. Install a jumper wire between relay terminal 85 and ground.
5. Test for less than 2 ohms between terminals 30 and 87. If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Relay Replacement (Attached to Wire Harness)»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) or «Relay Replacement (Within an Electrical Center)»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
2. «Power Brake Booster Auxiliary Pump Replacement»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
3. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Symptoms - Hydraulic Brakes

1. Perform «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) 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 module(s) can communicate via the serial data link.
2. Perform the «Brake System Vehicle Road Test»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) before using the hydraulic brake symptom tables in order to duplicate the customer's concern.
3. Review the system operation in order to familiarize yourself with the system functions. Refer to the following: «Brake Warning System Description and Operation»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Hydraulic Brake System Description and Operation»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Brake Assist System Description and Operation»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Disc Brake System Description and Operation»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-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/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
2. «Brake Pulsation»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-pulsation)
3. «Brake System Noise»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-noise)
4. «Braking Action Uneven - Pulls to One Side»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
5. «Braking Action Uneven - Front to Rear»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
6. «Brake Pedal Excessive Travel»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-pedal-excessive-travel)
7. «Brake Pedal Excessive Effort»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-pedal-excessive-effort)
8. «Brakes Drag»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brakes-drag)
9. «Brake System Slow Release»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-system-slow-release)
10. «Brake Fluid Loss»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__brake-fluid-loss)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/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 in «Circuit/System Testing»(/cadillac/cts/ii-2007-2014/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 in «Circuit/System Testing»(/cadillac/cts/ii-2007-2014/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 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»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system)
2. «Parking Brake Indicator Switch Replacement»(/cadillac/cts/ii-2007-2014/remont/parking-brake-system/#parking-brake-system)
3. «Control Module References»(/cadillac/cts/ii-2007-2014/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

Brake Pedal Excessive Effort

Brakes Drag

Brake System Slow Release

Brake Fluid Loss

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

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/cts/ii-2007-2014/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/cts/ii-2007-2014/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.

Tools Required

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/cts/ii-2007-2014/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/cts/ii-2007-2014/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: Maximum brake pedal travel (measured with the ignition OFF, brake booster power assist depleted, and the brakes cool): 63.5 mm (2.5 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.

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/cts/ii-2007-2014/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

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/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/cts/ii-2007-2014/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/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/cts/ii-2007-2014/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 GM approved brake fluid from a clean, sealed brake fluid container.

Removal Procedure

1. Remove the brake fluid from the master cylinder reservoir.
2. Disconnect the brake fluid level indicator switch electrical connector.
3. Remove the master cylinder reservoir bolts (1).
4. Remove the master cylinder reservoir (1). Carefully pull the reservoir straight upward.
5. Remove the master cylinder reservoir seals (1).
6. If installing a new master cylinder reservoir, remove the brake fluid level indicator switch. Refer to «Brake Fluid Level Indicator Switch Replacement»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .

Installation Procedure

1. If installing a new master cylinder reservoir, install the brake fluid level indicator switch. Refer to «Brake Fluid Level Indicator Switch Replacement»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
2. If installing the original master cylinder reservoir, clean the master cylinder reservoir with denatured alcohol and dry with filtered, non-lubricated compressed air.
3. Install the master cylinder reservoir seals (1). Lubricate the seals 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.
4. Install the master cylinder reservoir (1). Carefully press the reservoir straight downward.
5. Install the master cylinder reservoir bolts (1) and tighten to 8 N.m (71 lb in).
6. Connect the brake fluid level indicator switch electrical connector.
7. Fill the master cylinder reservoir. Refer to «Master Cylinder Reservoir Filling»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .

1. Remove the brake fluid from the master cylinder reservoir.
2. Disconnect the brake fluid level indicator switch electrical connector.
3. Remove the master cylinder reservoir bolts (1).
4. Remove the master cylinder reservoir (1). Carefully pull the reservoir straight upward.
5. Remove the master cylinder reservoir seals (1).
6. If installing a new master cylinder reservoir, remove the brake fluid level indicator switch. Refer to «Brake Fluid Level Indicator Switch Replacement»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .

1. If installing a new master cylinder reservoir, install the brake fluid level indicator switch. Refer to «Brake Fluid Level Indicator Switch Replacement»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
2. If installing the original master cylinder reservoir, clean the master cylinder reservoir with denatured alcohol and dry with filtered, non-lubricated compressed air.
3. Install the master cylinder reservoir seals (1). Lubricate the seals 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.
4. Install the master cylinder reservoir (1). Carefully press the reservoir straight downward.
5. Install the master cylinder reservoir bolts (1) and tighten to 8 N.m (71 lb in).
6. Connect the brake fluid level indicator switch electrical connector.
7. Fill the master cylinder reservoir. Refer to «Master Cylinder Reservoir Filling»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) .

1. With the engine OFF, apply and release the brake pedal several times until the pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.
2. Disconnect the brake fluid level indicator switch electrical connector.
3. Remove the air inlet panel support bracket push nut from the master cylinder mounting stud.
4. Carefully pull the air inlet panel support bracket outward and rotate the panel aside.
5. Disconnect the 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.
6. Disconnect the master cylinder secondary brake pipe fitting (1). Cap the brake pipe fitting and plug the master cylinder outlet port to prevent brake fluid loss and contamination.
7. Remove the master cylinder nuts (1).
8. Remove the master cylinder (1) from the power vacuum brake booster.
9. Inspect the master cylinder to power vacuum brake booster seal for damage and replace, if necessary.

1. Position the master cylinder to power vacuum brake booster seal to the groove in the master cylinder body. Ensure the seal is positioned properly and is not deformed.
2. If installing a new master cylinder, bench bleed the master cylinder. Refer to «Master Cylinder Bench Bleeding»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-bench-bleeding) .
3. Install the master cylinder (1) to the power vacuum brake booster.
4. Install the master cylinder nuts (1) and tighten to 25 N.m (18 lb ft).
5. Connect the master cylinder secondary brake pipe fitting (1) and tighten the fitting to 36 N.m (27 lb ft).
6. Connect the master cylinder primary brake pipe fitting (1) and tighten the fitting to 36 N.m (27 lb ft).
7. Connect the brake fluid level indicator switch electrical connector.
8. Rotate the air inlet panel and position the support bracket to the master cylinder mounting stud.
9. Install the air inlet panel support bracket push nut.
10. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .

1. With the engine OFF, apply and release the brake pedal several times to deplete the power vacuum brake booster vacuum reserve.
2. Disconnect the brake fluid level indicator switch electrical connector.
3. Disconnect the 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.
4. Disconnect the master cylinder secondary brake pipe fitting (1). Cap the brake pipe fitting and plug the master cylinder outlet port to prevent brake fluid loss and contamination.
5. Remove the master cylinder nuts (1).
6. Remove the master cylinder (1) from the power vacuum brake booster.
7. Inspect the master cylinder to power vacuum brake booster seal for damage and replace, if necessary.

1. Position the master cylinder to power vacuum brake booster seal to the master cylinder body. Ensure the seal is positioned properly and is not deformed.
2. If installing a new master cylinder, bench bleed the master cylinder. Refer to «Master Cylinder Bench Bleeding»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-bench-bleeding) .
3. Install the master cylinder (1) to the power vacuum brake booster.
4. Install the master cylinder nuts (1) and tighten to 25 N.m (18 lb ft).
5. Connect the master cylinder secondary brake pipe fitting (1) and tighten the fitting to 36 N.m (27 lb ft).
6. Connect the master cylinder primary brake pipe fitting (1) and tighten the fitting to 36 N.m (27 lb ft).
7. Connect the brake fluid level indicator switch electrical connector.
8. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .

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/cts/ii-2007-2014/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 8

1. Remove the power vacuum brake booster. Refer to «Power Vacuum Brake Booster Replacement (LHD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
2. For vehicles without the electronic parking brake, remove the park brake pedal assembly and front park brake cable and position aside. Refer to «Parking Brake Lever Pedal Assembly Replacement»(/cadillac/cts/ii-2007-2014/remont/parking-brake-system/#parking-brake-system) .
3. Without disconnecting the steering column from the intermediate shaft, lower and support the steering column. Refer to «Steering Column Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column) .
4. Disconnect the brake pedal position sensor (1) electrical connector.
5. Remove the power vacuum brake booster pushrod nut (1).
6. Disconnect the power vacuum brake booster pushrod (1) from the brake pedal pivot.
7. Remove the power vacuum brake booster pushrod bushing (1).
8. Remove the power vacuum brake booster bracket nuts (1).
9. Remove the brake pedal bracket nuts (1).
10. Remove the upper steering column support bracket nuts (1).
11. Remove the power vacuum brake booster bracket (1).
12. Remove the steering column support bracket (1).
13. Remove the brake pedal assembly (1) from the vehicle.

1. Install the brake pedal assembly (1) to the vehicle.
2. Install the steering column support bracket (1).
3. Install the power vacuum brake booster bracket (1).
4. Install the upper steering column support bracket nuts (1) and tighten to 25 N.m (18 lb ft).
5. Install the brake pedal bracket nuts (1) and tighten to 25 N.m (18 lb ft).
6. Install the power vacuum brake booster bracket nuts (1) and tighten to 25 N.m (18 lb ft).
7. Install the power vacuum brake booster pushrod bushing (1).
8. Connect the power vacuum brake booster pushrod (1) to the brake pedal pivot.
9. Install the power vacuum brake booster pushrod nut (1) and tighten to 9 N.m (80 lb in).
10. Connect the brake pedal position sensor (1) electrical connector.
11. Install the steering column. Refer to «Steering Column Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column) .
12. If removed, install the park brake pedal assembly. Refer to «Parking Brake Lever Pedal Assembly Replacement»(/cadillac/cts/ii-2007-2014/remont/parking-brake-system/#parking-brake-system) .
13. Install the power vacuum brake booster. Refer to «Power Vacuum Brake Booster Replacement (LHD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
14. Calibrate the brake pedal position sensor. Refer to «Brake Pedal Position Sensor Calibration»(/cadillac/cts/ii-2007-2014/remont/exterior-lights/#lighting-system__brake-pedal-position-sensor-calibration) .

1. Remove the power vacuum brake booster. Refer to «Power Vacuum Brake Booster Replacement (RHD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
2. Without disconnecting the steering column from the intermediate shaft, lower and support the steering column. Refer to «Steering Column Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column) .
3. Disconnect the brake pedal position sensor (1) electrical connector.
4. Remove the power vacuum brake booster pushrod nut (1).
5. Disconnect the power vacuum brake booster pushrod from the brake pedal pivot.
6. Remove the power vacuum brake booster pushrod bushing (1).
7. Remove the power vacuum brake booster bracket nuts (1).
8. Remove the brake pedal bracket nuts (1).
9. Remove the upper steering column support bracket nuts (1).
10. Remove the power vacuum brake booster bracket (1).
11. Remove the steering column support bracket (1).
12. Remove the brake pedal assembly (1) from the vehicle.

1. Install the brake pedal assembly (1) to the vehicle.
2. Install the steering column support bracket (1).
3. Install the power vacuum brake booster bracket (1).
4. Install the upper steering column support bracket nuts (1) and tighten to 25 N.m (18 lb ft).
5. Install the brake pedal bracket nuts (1) and tighten to 25 N.m (18 lb ft).
6. Install the power vacuum brake booster bracket nuts (1) and tighten to 25 N.m (18 lb ft).
7. Install the power vacuum brake booster pushrod bushing (1).
8. Connect the power vacuum brake booster pushrod to the brake pedal pivot.
9. Install the power vacuum brake booster pushrod nut (1) and tighten to 9 N.m (80 lb in).
10. Connect the brake pedal position sensor (1) electrical connector.
11. Install the steering column. Refer to «Steering Column Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column) .
12. Install the power vacuum brake booster. Refer to «Power Vacuum Brake Booster Replacement (RHD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
13. Calibrate the brake pedal position sensor. Refer to «Brake Pedal Position Sensor Calibration»(/cadillac/cts/ii-2007-2014/remont/exterior-lights/#lighting-system__brake-pedal-position-sensor-calibration) .

Special Tools

J-45405: Pipe Flaring Tool Kit

For equivalent regional tools, refer to Special Tools .

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: Pipe Flaring Tool Kit . 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: Pipe Flaring Tool Kit, carefully cut the brake pipe squarely to the measured length.
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: Pipe Flaring Tool Kit , by unthreading the blade block from the stripping tool and installing the block with the desired blade facing the tool rollers. 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: Pipe Flaring Tool Kit.
11. Install the tube nuts on the brake pipe, noting their orientation.
12. Clean the brake pipe and the J-45405: Pipe Flaring Tool Kit of lubricant, contaminants, and debris.
13. Loosen the die clamping screw of the J-45405: Pipe Flaring Tool Kit.
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: Pipe Flaring Tool Kit until it bottoms against the die cage.
23. While guiding the forming mandrel into the exposed end of pipe to be flared, operate the lever of the J-45405: Pipe Flaring Tool Kit until the forming mandrel bottoms against the clamping dies.
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: Pipe Flaring Tool Kit until it bottoms against the die cage.
28. While guiding the finishing cone into the exposed end of pipe to be flared, operate the lever of the J-45405: Pipe Flaring Tool Kit until the finishing cone bottoms against the dies.
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/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/cts/ii-2007-2014/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. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#general-information) .
2. Remove the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/cts/ii-2007-2014/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
3. Disconnect the front brake pipe fitting (1). Cap the brake pipe fitting to prevent brake fluid loss and contamination.
4. Remove the front brake hose retainer clip (1).
5. Remove the rear lower shock module bolt (1).
6. Remove the brake hose fitting bolt (1).
7. Remove the brake hose fitting gaskets (2) from the brake hose (3). Discard the brake hose fitting gaskets.
8. Remove the brake hose.

1. Assemble the brake hose fitting bolt (1) with 2 new brake hose fitting gaskets (2) to the brake hose (3).
2. Install the brake hose assembly to the caliper. Tighten: Tighten the brake hose fitting bolt to 49 N.m (36 lb ft).
3. Install the rear lower shock module bolt (1) through the brake hose bracket and to the lower control arm. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
4. Install the front brake hose retainer clip (1).
5. Connect the front brake pipe fitting (1). Tighten: Tighten the fitting to 18 N.m (13 lb ft).
6. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
7. Install the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/cts/ii-2007-2014/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#general-information) .
2. Remove the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/cts/ii-2007-2014/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
3. Disconnect the front brake pipe fitting (1). Cap the brake pipe fitting to prevent brake fluid loss and contamination.
4. Remove the front brake hose retainer clip (1).
5. Remove the brake hose retainer bolt (1).
6. Disconnect the wheel speed sensor wire harness clip (2) from the brake hose retainer.
7. Remove the brake hose fitting bolt (1).
8. Remove the brake hose fitting gaskets (2) from the brake hose (3). Discard the brake hose fitting gaskets.
9. Remove the brake hose.

1. Assemble the brake hose fitting bolt (1) with 2 new brake hose fitting gaskets (2) to the brake hose (3).
2. Install the brake hose assembly to the caliper. Tighten: Tighten the brake hose fitting bolt to 49 N.m (36 lb ft).
3. Install the brake hose retainer bolt (1). Tighten: Tighten the brake hose retainer bolt to 10 N.m (89 lb in).
4. Connect the wheel speed sensor wire harness clip (2) to the brake hose retainer.
5. Install the front brake hose retainer clip (1).
6. Connect the front brake pipe fitting (1). Tighten: Tighten the fitting to 18 N.m (13 lb ft).
7. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
8. Install the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/cts/ii-2007-2014/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#general-information) .
2. Remove the right rear tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/cts/ii-2007-2014/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
3. Clean all dirt and foreign material from the brake hose and the brake pipe fittings.
4. Disconnect the crossover brake pipe fitting (1) from the intermediate brake hose assembly (3). Cap the brake pipe fitting to prevent brake fluid loss and contamination.
5. Using a flat-bladed tool, remove the brake hose retainer (2) from the rear frame bracket.
6. Disconnect the brake pipe fittings from the intermediate brake hose assembly. Cap the brake pipe fittings to prevent brake fluid loss and contamination.
7. Disconnect the brake hose fitting bolt (4) from the brake caliper (1).
8. Disconnect the brake hose from the brake caliper. Plug the brake caliper inlet port to prevent brake fluid loss and contamination.
9. Place a shop towel on a hard surface.
10. Tap the threaded end of the brake hose fitting bolt on the shop towel to remove the gaskets (3) from the bolt (4)
11. Remove and discard the 2 copper brake hose gaskets (3). These gaskets may be stuck to the brake caliper and/or the brake hose end (2).
12. Remove the intermediate brake hose assembly mounting nuts (1) from the studs.
13. Remove the intermediate brake hose assembly (2) from the vehicle.

1. Install the intermediate brake hose assembly (2) to the mounting studs.
2. Install the intermediate brake hose assembly mounting nuts (1) to the mounting studs and tighten to 10 N.m (89 lb in).
3. Connect the 2 brake pipe fittings to the intermediate brake hose assembly.
4. Remove the plug from the brake caliper inlet port.
5. Assemble the brake hose (2), the NEW copper brake hose gaskets (3), and the brake hose fitting bolt (4) to the brake hose.
6. Install the brake hose fitting bolt to the brake caliper (1) and tighten to 49 N.m (36 lb ft).
7. Install the brake hose retainer (2) to the rear frame bracket.
8. Connect the crossover brake pipe fitting (1) to the intermediate brake hose assembly (3) and tighten to 18 N.m (13 lb ft).
9. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
10. Install the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/cts/ii-2007-2014/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#general-information) .
2. Remove the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/cts/ii-2007-2014/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
3. Disconnect the rear brake pipe fitting (1). Cap the brake pipe fitting to prevent brake fluid loss and contamination.
4. Remove the front brake hose retainer clip (1).
5. Remove the brake hose fitting bolt (1).
6. Remove the brake hose fitting gaskets (2) from the brake hose (3). Discard the brake hose fitting gaskets.
7. Remove the brake hose.

1. Assemble the brake hose fitting bolt (1) with 2 new brake hose fitting gaskets (2) to the brake hose (3).
2. Install the brake hose assembly to the caliper and tighten to 49 N.m (36 lb ft).
3. Install the rear brake hose retainer clip (1).
4. Connect the rear brake pipe fitting (1) and tighten to 18 N.m (13 lb ft).
5. Bleed the hydraulic brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .
6. Install the tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/cadillac/cts/ii-2007-2014/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .

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. 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. 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, inboard (fixed caliper), 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.
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. For fixed caliper models, repeat steps 5-11 for the outboard bleeder valve.
13. With the right rear wheel hydraulic circuit bleeder valve, or valves (fixed caliper), 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, inner (fixed caliper), bleeder valve.
14. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
15. For fixed caliper models, repeat steps 5-11 for the outboard bleeder valve.
16. With the left front wheel hydraulic circuit bleeder valve, or valves (fixed caliper), 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, inner (fixed caliper), bleeder valve.
17. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
18. For fixed caliper models, repeat steps 5-11 for the outboard bleeder valve.
19. With the left rear wheel hydraulic circuit bleeder valve, or valves (fixed caliper), 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, inner (fixed caliper), bleeder valve.
20. Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
21. For fixed caliper models, repeat steps 5-11 for the outboard bleeder valve.
22. After completing the final wheel hydraulic circuit bleeding procedure, ensure that each of the 4 wheel hydraulic circuit bleeder valves, or 8 bleeder valves (fixed caliper), are properly tightened.
23. Fill the brake master cylinder reservoir to the maximum-fill level with GM approved brake fluid from a clean, sealed brake fluid container.
24. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
25. 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/cts/ii-2007-2014/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.
26. Turn the ignition key ON, with the engine OFF. Check to see if the brake system warning lamp remains illuminated.
27. If the brake system warning lamp remains illuminated. Refer to «Symptoms - Hydraulic Brakes»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system__symptoms-hydraulic-brakes) .

Special Tools

1. J-29532: Diaphragm Type Brake Pressure Bleeder, or equivalent
2. J-35589-A: Master Cylinder 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 GM approved 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 GM approved 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: Master Cylinder Bleeder Adapter to the brake master cylinder reservoir.
6. Check the brake fluid level in the J-29532: Diaphragm Type Brake Pressure Bleeder, or equivalent. Add GM approved 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 Type Brake Pressure Bleeder, or equivalent, to the J-35589-A: Master Cylinder Bleeder Adapter.
8. Charge the J-29532: Diaphragm Type Brake Pressure Bleeder, or equivalent, air tank to 175-205 kPa (25-30 psi).
9. Open the J-29532: Diaphragm Type Brake 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, inboard (fixed caliper), 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 GM approved 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. For fixed caliper models, repeat steps 11-14 for the outboard bleeder valve.
16. With the right rear wheel hydraulic circuit bleeder valve, or valves (fixed caliper), 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, inboard (fixed caliper), bleeder valve.
17. Install a transparent hose over the end of the bleeder valve, then repeat steps 13-14.
18. For fixed caliper models, repeat steps 11-14 for the outboard bleeder valve.
19. With the left front wheel hydraulic circuit bleeder valve, or valves (fixed caliper), 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, inner (fixed caliper), bleeder valve.
20. Install a transparent hose over the end of the bleeder valve, then repeat steps 13-14.
21. For fixed caliper models, repeat steps 11-14 for the outboard bleeder valve.
22. With the left rear wheel hydraulic circuit bleeder valve, or valves (fixed caliper), 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, inner (fixed caliper), bleeder valve.
23. Install a transparent hose over the end of the bleeder valve, then repeat steps 13-14.
24. For fixed caliper models, repeat steps 11-14 for the outboard bleeder valve.
25. After completing the final wheel hydraulic circuit bleeding procedure, ensure that each of the 4 wheel hydraulic circuit bleeder valves, or 8 bleeder valves (fixed caliper), are properly tightened.
26. Close the J-29532: Diaphragm Type Brake Pressure Bleeder, or equivalent, fluid tank valve, then disconnect the J-29532: Diaphragm Type Brake Pressure Bleeder, or equivalent, from the J-35589-A: Master Cylinder Bleeder Adapter.
27. Remove the J-35589-A: Master Cylinder Bleeder Adapter from the brake master cylinder reservoir.
28. Fill the brake master cylinder reservoir to the maximum-fill level with GM approved brake fluid from a clean, sealed brake fluid container.
29. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
30. 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/cts/ii-2007-2014/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 BPMV. Refer to «Antilock Brake System Automated Bleed»(/cadillac/cts/ii-2007-2014/remont/anti-locktraction-control/#antilock-brake-system-with-traction-control-system-stability-control-system__antilock-brake-system-automated-bleed) .
31. Turn the ignition key ON, with the engine OFF. Check to see if the brake system warning lamp remains illuminated.
32. If the brake system warning lamp remains illuminated. Refer to «Symptoms - Hydraulic Brakes»(/cadillac/cts/ii-2007-2014/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 2 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 (LHD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Master Cylinder Replacement (RHD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Hose Replacement (RWD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Hose Replacement (AWD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Brake Intermediate Hose Replacement»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Rear Brake Hose Replacement»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Caliper Replacement (JE5, J55 (RWD))»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system) «Front Brake Caliper Replacement (JE5, J55 (AWD))»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system) «Front Brake Caliper Replacement (J56)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system) «Rear Brake Caliper Replacement (JE5, J55)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system) «Rear Brake Caliper Replacement (J56)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system) «Brake Pressure Modulator Valve Replacement (CTS)»(/cadillac/cts/ii-2007-2014/remont/anti-locktraction-control/#antilock-brake-system-with-traction-control-system-stability-control-system) «Brake Pressure Modulator Valve Replacement (CTS-V)»(/cadillac/cts/ii-2007-2014/remont/anti-locktraction-control/#antilock-brake-system-with-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: «Master Cylinder Replacement (LHD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Master Cylinder Replacement (RHD)»(/cadillac/cts/ii-2007-2014/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 (LHD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Master Cylinder Reservoir Replacement (RHD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) . Replace the brake master cylinder reservoir cap diaphragm. «Front Brake Hose Replacement (RWD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Hose Replacement (AWD)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Brake Intermediate Hose Replacement»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Rear Brake Hose Replacement»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) «Front Brake Caliper Overhaul (JE5, J55)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system__front-brake-caliper-overhaul-je5-j55) «Front Brake Caliper Overhaul (J56)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system__front-brake-caliper-overhaul-j56) or «Front Brake Caliper Replacement (JE5, J55 (RWD))»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system) «Front Brake Caliper Replacement (JE5, J55 (AWD))»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system) «Front Brake Caliper Replacement (J56)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system) «Rear Brake Caliper Overhaul (JE5, J55)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system__rear-brake-caliper-overhaul-je5-j55) «Rear Brake Caliper Overhaul (J56)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system__rear-brake-caliper-overhaul-j56) or «Rear Brake Caliper Replacement (JE5, J55)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system) «Rear Brake Caliper Replacement (J56)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#disc-brake-system) «Brake Pressure Modulator Valve Replacement (CTS)»(/cadillac/cts/ii-2007-2014/remont/anti-locktraction-control/#antilock-brake-system-with-traction-control-system-stability-control-system) «Brake Pressure Modulator Valve Replacement (CTS-V)»(/cadillac/cts/ii-2007-2014/remont/anti-locktraction-control/#antilock-brake-system-with-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 which 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) 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/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/cts/ii-2007-2014/remont/mechanical-hydraulic/#hydraulic-brake-system) .

J-22805-B: Brake Booster Holder

1. Remove the left side instrument panel insulator panel. Refer to «Instrument Panel Insulator Replacement - Left Side (Left Hand Drive)»(/cadillac/cts/ii-2007-2014/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
2. Disconnect the brake pedal position sensor electrical connector (1).
3. Remove the power vacuum brake booster pushrod nut (1).
4. Disconnect the power vacuum brake booster pushrod from the brake pedal pivot.
5. Remove the cross vehicle brace, if equipped. Refer to «Cross Vehicle Brace Replacement»(/cadillac/cts/ii-2007-2014/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
6. Disconnect the brake fluid level indicator switch electrical connector.
7. Disconnect the power vacuum brake booster check valve and hose assembly (1).
8. Remove the master cylinder nuts (1).
9. Without disconnecting the brake pipe fittings, position aside the master cylinder (1) and support with heavy mechanics wire or equivalent.
10. Remove the air inlet grille panel. Refer to «Air Inlet Grille Panel Replacement»(/cadillac/cts/ii-2007-2014/remont/wiperwasher-systems/#wiper-system-and-washer-system) .
11. Without disconnecting the hoses, remove and position aside the surge tank. Refer to «Radiator Surge Tank Replacement»(/cadillac/cts/ii-2007-2014/remont/cooling-system-mechanical/#engine-cooling-system) .
12. Modify the J-22805-B: Brake Booster Holder to accommodate the narrower span between the master cylinder mounting studs on the power vacuum brake booster: Using a suitable grinding tool or metal file, elongate the mounting holes of the J-22805-B: Brake Booster Holder. Remove approximately 6.36 mm (0.25 in) of material from the inner edges of both mounting holes. Remove material from the inner edges of the mounting until the span, from center to center, is approximately 80.00 mm (3.15 in).
13. Install the J-22805-B: Brake Booster Holder (1) and secure with the master cylinder nuts.
14. Using a flat-bladed tool, depress the locking tab (2) toward the cowl.
15. Rotate the J-22805-B: Brake Booster Holder and power vacuum brake booster (1) counterclockwise and release the power vacuum brake booster from the bracket.
16. Carefully pull the power vacuum brake booster forward slightly and support the power vacuum booster to access the booster pushrod retaining clip.
17. Compress the power vacuum brake booster foam filter to access the power vacuum brake booster pushrod retaining clip.
18. Disconnect the power vacuum brake booster pushrod (1) from the booster by releasing the retaining clip (2).
19. Remove the power vacuum brake booster from the vehicle.
20. Remove the power vacuum brake booster pushrod through the dust boot from inside of the vehicle, if necessary.

1. Install the power vacuum brake booster pushrod through the dust boot from inside of the vehicle, if removed.
2. Install the vacuum brake booster to the vehicle.
3. Compress the power vacuum brake booster foam filter to access the vacuum brake booster pushrod retaining clip.
4. Connect the power vacuum brake booster pushrod (1) to the booster and engage the retaining clip (2).
5. Position the power vacuum brake booster to the booster bracket.
6. Using the J-22805-B: Brake Booster Holder (1), rotate the power vacuum brake booster clockwise until the locking tab (2) engages the booster bracket flange. Ensure the booster locking tab fully engages in the bracket.
7. Remove the J-22805-B: Brake Booster Holder from the power vacuum brake booster and discard the master cylinder nuts.
8. Install the master cylinder (1) to the power vacuum brake booster.
9. Install new master cylinder nuts (1) and tighten to 25 N.m (18 lb ft).
10. Connect the power vacuum brake booster check valve and hose assembly (1). If necessary, a small amount of denatured alcohol may be used as a lubricant for assembly. Do not use soap.
11. Connect the brake fluid level indicator switch electrical connector.
12. Install the air inlet grille panel. Refer to «Air Inlet Grille Panel Replacement»(/cadillac/cts/ii-2007-2014/remont/wiperwasher-systems/#wiper-system-and-washer-system) .
13. Install the surge tank. Refer to «Radiator Surge Tank Replacement»(/cadillac/cts/ii-2007-2014/remont/cooling-system-mechanical/#engine-cooling-system) .
14. Install the cross vehicle brace, if removed. Refer to «Cross Vehicle Brace Replacement»(/cadillac/cts/ii-2007-2014/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
15. Connect the power vacuum brake booster pushrod to the brake pedal pivot.
16. Install the power vacuum brake booster pushrod nut (1) and tighten to 9 N.m (80 lb in).
17. Connect the brake pedal position sensor electrical connector (1).
18. Calibrate the brake pedal position sensor. Refer to «Brake Pedal Position Sensor Calibration»(/cadillac/cts/ii-2007-2014/remont/exterior-lights/#lighting-system__brake-pedal-position-sensor-calibration) .
19. Install the left side instrument panel insulator panel. Refer to «Instrument Panel Insulator Replacement - Left Side (Left Hand Drive)»(/cadillac/cts/ii-2007-2014/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .

J-22805-B: Brake Booster Holder

1. Remove the right side instrument panel insulator panel. Refer to «Instrument Panel Insulator Replacement - Right Side (Right Hand Drive)»(/cadillac/cts/ii-2007-2014/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
2. Without disconnecting the steering column from the intermediate shaft, lower and support the steering column. Refer to «Steering Column Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column) .
3. Disconnect the brake pedal position sensor electrical connector (1).
4. Remove the power vacuum brake booster pushrod nut (1).
5. Disconnect the power vacuum brake booster pushrod from the brake pedal pivot.
6. Remove the cross vehicle brace, if equipped. Refer to «Cross Vehicle Brace Replacement»(/cadillac/cts/ii-2007-2014/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
7. Disconnect the brake fluid level indicator switch electrical connector.
8. Remove the master cylinder nuts (1).
9. Without disconnecting the brake pipe fittings, position aside the master cylinder (1) and support with heavy mechanics wire or equivalent.
10. Disconnect the power vacuum brake booster check valve and hose assembly (1).
11. Modify the J-22805-B: Brake Booster Holder to accommodate the narrower span between the master cylinder mounting studs on the power vacuum brake booster: Using a suitable grinding tool or metal file, elongate the mounting holes of the J-22805-B: Brake Booster Holder. Remove approximately 6.36 mm (0.25 in) of material from the inner edges of both mounting holes. Remove material from the inner edges of the mounting until the span, from center to center, is approximately 80.00 mm (3.15 in).
12. Install the J-22805-B: Brake Booster Holder (1) and secure with the master cylinder nuts.
13. Using a flat-bladed tool, depress the locking tab (2) toward the cowl.
14. Rotate the J-22805-B: Brake Booster Holder and power vacuum brake booster (1) counterclockwise and release the power vacuum brake booster from the bracket.
15. Carefully pull the power vacuum brake booster forward slightly and support the power vacuum booster to access the booster pushrod retaining clip.
16. Compress the power vacuum brake booster foam filter to access the power vacuum brake booster pushrod retaining clip.
17. Disconnect the power vacuum brake booster pushrod (1) from the booster by releasing the retaining clip (2).
18. Remove the power vacuum brake booster from the vehicle.
19. Remove the power vacuum brake booster pushrod through the dust boot from inside of the vehicle, if necessary.

1. Install the power vacuum brake booster pushrod through the dust boot from inside of the vehicle, if removed.
2. Install the vacuum brake booster to the vehicle.
3. Compress the power vacuum brake booster foam filter to access the vacuum brake booster pushrod retaining clip.
4. Connect the power vacuum brake booster pushrod (1) to the booster and engage the retaining clip (2).
5. Position the vacuum power brake booster (1) to the booster bracket.
6. Using the J-22805-B: Brake Booster Holder (1), rotate the power vacuum brake booster clockwise until the locking tab (2) engages the booster bracket flange. Ensure the booster locking tab fully engages in the bracket.
7. Remove the J-22805-B: Brake Booster Holder from the power vacuum brake booster and discard the master cylinder nuts.
8. Connect the power vacuum brake booster check valve and hose assembly (1). If necessary, a small amount of denatured alcohol may be used as a lubricant for assembly. Do not use soap.
9. Install the master cylinder (1) to the power vacuum brake booster.
10. Install new master cylinder nuts (1) and tighten to 25 N.m (18 lb ft).
11. Connect the brake fluid level indicator switch electrical connector.
12. Install the cross vehicle brace, if removed. Refer to «Cross Vehicle Brace Replacement»(/cadillac/cts/ii-2007-2014/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
13. Connect the power vacuum brake booster pushrod to the brake pedal pivot.
14. Install the power vacuum brake booster pushrod nut (1) and tighten to 9 N.m (80 lb in).
15. Connect the brake pedal position sensor electrical connector (1).
16. Install the steering column. Refer to «Steering Column Replacement»(/cadillac/cts/ii-2007-2014/remont/steering-column-switches/#steering-wheel-steering-column) .
17. Calibrate the brake pedal position sensor. Refer to «Brake Pedal Position Sensor Calibration»(/cadillac/cts/ii-2007-2014/remont/exterior-lights/#lighting-system__brake-pedal-position-sensor-calibration) .
18. Install the right side instrument panel insulator panel. Refer to «Instrument Panel Insulator Replacement - Right Side (Right Hand Drive)»(/cadillac/cts/ii-2007-2014/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .

1. Apply the brake pedal several times until the pedal becomes firm to deplete the vacuum reserve in the brake booster.
2. Remove the fuel injector sight shield and intake manifold insulator. Refer to «Fuel Injector Sight Shield Replacement (LF1, LY7)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) or «Fuel Injector Sight Shield Replacement (LLT)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) .
3. Remove the check valve (1) from the vacuum brake booster.
4. Remove and discard the vacuum hose clamp (1).
5. Remove the vacuum hose (2) from the vacuum port on the LH side of the intake manifold.
6. Release the vacuum brake booster hose quick connect (1) from the power brake booster auxiliary pump.
7. Remove the check valve from the vacuum brake booster hose, if necessary.

1. Install the vacuum brake booster hose quick connect (1) to the power brake booster auxiliary pump.
2. Position a new hose clamp (1) to the vacuum brake booster hose.
3. Install the vacuum hose (2) to the vacuum port on the LH side of the intake manifold.
4. Using a suitable tool, compress the clamp to secure the vacuum brake booster hose to the vacuum port fitting.
5. Install the check valve to the vacuum brake booster hose, if removed.
6. Install the check valve (1) to the vacuum brake booster.
7. Install the fuel injector sight shield and intake manifold insulator. Refer to «Fuel Injector Sight Shield Replacement (LF1, LY7)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) or «Fuel Injector Sight Shield Replacement (LLT)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) .

1. With the engine OFF, apply and release the brake pedal several times until the brake pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.
2. Remove the fuel injector sight shield and intake manifold insulator. Refer to «Fuel Injector Sight Shield Replacement (LF1, LY7)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) or «Fuel Injector Sight Shield Replacement (LLT)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) .
3. Remove the power vacuum brake booster check valve and hose assembly (1) from the power vacuum brake booster.
4. Remove and discard the vacuum hose clamp (1).
5. Remove the vacuum hose (2) from the vacuum port on the LH side of the intake manifold.
6. Release the power vacuum brake booster hose quick connect (1) from the power vacuum brake booster auxiliary pump.
7. Remove the check valve from the power vacuum brake booster hose, if necessary.

1. Install the power vacuum brake booster hose quick connect (1) to the power vacuum brake booster auxiliary pump.
2. Position a new hose clamp (1) to the power vacuum brake booster hose.
3. Install the vacuum hose (2) to the vacuum port on the LH side of the intake manifold.
4. Using a suitable tool, compress the clamp to secure the power vacuum brake booster hose to the vacuum port fitting.
5. Install the check valve to the power vacuum brake booster hose, if removed.
6. Install the power vacuum brake booster check valve and hose assembly (1) to the power vacuum brake booster.
7. Install the fuel injector sight shield and intake manifold insulator. Refer to «Fuel Injector Sight Shield Replacement (LF1, LY7)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) or «Fuel Injector Sight Shield Replacement (LLT)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) .

1. With the engine OFF, apply and release the brake pedal several times until the pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.
2. Remove the front intake manifold cover. Refer to «Intake Manifold Cover Replacement - Front»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-62l-repair-instructions-on-vehicle) .
3. Remove the vacuum brake booster check valve and hose (1) assembly from the power vacuum brake booster.
4. Disconnect the vacuum brake booster hose (1) from the vacuum port at the front of the engine intake manifold.
5. Remove the vacuum brake booster check valve and hose assembly from the vehicle.

1. Install the vacuum brake booster hose (1) to the vacuum port at the front of the engine intake manifold.
2. Install the vacuum brake booster check valve and hose (1) assembly to the power vacuum brake booster.
3. Install the front intake manifold cover. Refer to «Intake Manifold Cover Replacement - Front»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-62l-repair-instructions-on-vehicle) .

1. Turn the engine OFF.
2. Apply and release the brake pedal several times until the pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.
3. Disconnect the power brake booster vacuum sensor electrical connector.
4. Remove the power brake booster vacuum sensor (1).
5. Remove the power brake booster vacuum sensor grommet (1).

1. Install the power brake booster vacuum sensor grommet (1).
2. Install the power brake booster vacuum sensor (1).
3. Connect the power brake booster vacuum sensor electrical connector.

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement (LF1, LY7)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) or «Fuel Injector Sight Shield Replacement (LLT)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) .
2. Release the power brake booster auxiliary pump hose quick connect (1).
3. Disconnect the power brake booster auxiliary pump electrical connector.
4. Remove the power brake booster auxiliary pump bracket M6 bolt (1).
5. Remove the power brake booster auxiliary pump bracket M12 bolt (2).
6. Remove the power brake booster auxiliary pump from the engine.
7. Remove the power brake booster auxiliary pump bolts (1) and nuts (2).
8. Remove the power brake booster auxiliary pump insulator sleeves (1).
9. Remove the power brake booster auxiliary pump insulators (2).
10. Release the power brake booster auxiliary pump electrical harness connector (3) from the bracket and remove the pump.

1. Assemble the power brake booster auxiliary pump sleeves (1) to the insulators (2).
2. Install the power brake booster auxiliary pump insulators.
3. Position the power brake booster auxiliary pump to the bracket and secure the electrical harness connector (3).
4. Install the power brake booster auxiliary pump bolts (1) and nuts (2) and tighten the bolts to 22 N.m (16 lb ft).
5. Install the power brake booster auxiliary pump assembly to the engine.
6. Install the power brake booster auxiliary pump bracket M6 bolt (1) and tighten to 10 N.m (89 lb in).
7. Install the power brake booster auxiliary pump bracket M12 bolt (2) and tighten to 70 N.m (52 lb ft).
8. Install the power brake booster auxiliary pump hose quick connect (1).
9. Connect the power brake booster auxiliary pump electrical connector.
10. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement (LF1, LY7)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) or «Fuel Injector Sight Shield Replacement (LLT)»(/cadillac/cts/ii-2007-2014/remont/mechanical/#engine-mechanical-30l-or-36l-repair-instructions-on-vehicle-1-of-2) .

System Component Description

The brake assist system consists of the following

System Operation

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.

The brake booster vacuum assist system consists of the following

The electronic brake control module (EBCM) actuates the brake booster vacuum pump to generate additional vacuum to the vacuum brake booster if low vacuum is detected by the brake vacuum sensor.

The IPC illuminates the BRAKE indicator and sends a serial data message in order to activate an audible warning when the following occurs

1. The IPC detects that the park brake is applied-signal circuit is low.
2. The IPC detects a low brake fluid condition-signal circuit is low.
3. The electronic brake control module (EBCM) detects a malfunction with the antilock brake system. The IPC receives a serial data message from the EBCM requesting illumination.
4. The IPC detects a loss of communications with the EBCM and the discrete back-up ABS indicator signal is open.
5. The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 5 seconds.
6. The brake indicator will flash to indicate a fault with the electroinc park brake system with the ignition key in the ON or OFF position.

CHECK BRAKE FLUID

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

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.

Illustration Tool Number/ Description J 22805-B Brake Booster Holder J 28662 Brake Pedal Effort Gauge J 29532 Diaphragm Pressure Bleeder J 35589-A Master Cylinder Bleeder Adapter J 45405 Pipe Flaring Tool Kit

Scheme 9

Scheme 10

Scheme 11

Scheme 12

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
• Relay Replacement (Attached to Wire Harness)
• ABS Description and Operation
• Disc Brake System Description and Operation
• Checking Aftermarket Accessories
• Parking Brake Indicator Switch Replacement
• Diagnostic Starting Point - Vehicle
• Park Brake System Diagnosis
• Front Disc Brake Mounting and Hardware Inspection
• Rear Disc Brake Mounting and Hardware Inspection
• Front Brake Caliper Overhaul (JE5, J55)
• Front Brake Caliper Overhaul (J56)
• Rear Brake Caliper Overhaul (JE5, J55)
• Rear Brake Caliper Overhaul (J56)
• Wheel Drive Shaft Outer Joint Inspection
• Brake Rotor Thickness Measurement
• Brake Rotor Thickness Variation Measurement
• Brake Rotor Surface and Wear Inspection
• Brake Rotor Refinishing
• Front Brake Rotor Replacement (JE5, J55 (RWD))
• Front Brake Rotor Replacement (J56)
• Rear Brake Rotor Replacement (JE5, J55)
• Rear Brake Rotor Replacement (J56)
• Brake Rotor Assembled Lateral Runout Measurement
• Brake Rotor Assembled Lateral Runout Correction
• Brake Pressure Modulator Valve Replacement (CTS)
• Lifting and Jacking the Vehicle
• Tire and Wheel Removal and Installation
• Brake Fluid Irritant Warning
• Brake Fluid Effects on Paint and Electrical Components Caution
• Fastener Caution
• Steering Column Replacement
• Brake Pedal Position Sensor Calibration
• Brake Dust Warning
• Antilock Brake System Automated Bleed
• Instrument Panel Insulator Replacement - Left Side (Left Hand Drive)
• Cross Vehicle Brace Replacement
• Air Inlet Grille Panel Replacement
• Radiator Surge Tank Replacement
• Fuel Injector Sight Shield Replacement (LF1, LY7)
• Intake Manifold Cover Replacement - Front
• DTC C0267
• Brake Fluid Loss
• Brake System Vacuum Source Test
• Brake Pulsation
• Brake System Noise
• Brake Pedal Excessive Travel
• Brake Pedal Excessive Effort
• Brakes Drag
• Brake System Slow Release
• Brake Assist System Diagnosis
• Brake Pedal Pushrod Inspection
• Master Cylinder Reservoir Filling
• Hydraulic Brake Component Operation Visual Inspection
• Brake Pipe and Hose Inspection
• Brake System Internal Leak Test
• Symptoms - Hydraulic Brakes
• Brake System External Leak Inspection
• Master Cylinder Bench Bleeding