Brake Master Cylinder Replacement - With Power Brake Booster and Electronic Brake Control Module
Single Use Fasteners and Components
  • Brake Master Cylinder Gasket
  • Brake Master Cylinder Reservoir
  • Brake Master Cylinder Reservoir Seal[3x]

Warning: The battery must be disconnected to prevent the brake master cylinder from pressurizing the hydraulic system during its automated self diagnostic tests that can possibly occur when a door is opened or the key transmitter is activated. Failure to follow this precaution may cause personal injury.

Warning: Refer to Brake Fluid Irritant Warning.

Caution: Refer to Brake Fluid Effects on Paint and Electrical Components Caution.

Note: Use all components included with the service kit.

Removal Procedure

  1. Open the hood.

    2. Warning: Always ensure the Battery Maintenance Mode is inactive before disconnecting the low voltage 12 volt battery (or batteries). This mode can be active with the ignition off, regardless of whether the vehicle charging cord is plugged in or not. When this mode is active, the on-board high voltage battery charger(s) will energize the 12 volt battery cables and charge the 12 volt battery (or batteries). Disconnecting any battery cables while this mode is active may result in an electrical shock or a burn from hot battery cable leads.

  2. Check the 12 volt battery voltage with a digital multimeter before disconnecting any battery cables leads. If the voltage is 13.5 volts or above, the Battery Maintenance Mode is active. The technician must wait for the T18 battery charger to deactivate before disconnecting the battery negative cable. Charging System Description and Operation
  3. Disconnect the battery negative cable.Battery Negative Cable Disconnection and Connection

    4. Object ID: 5918320
  4. Brake Pedal Push Rod Bolt(1)»Remove
  5. Brake Pedal Nut(2)»Remove[4x]

    6. Object ID: 5840625
  6. With the aid of an assistant, remove the fascia.(1)Front Bumper Fascia Removal and Installation

    7. Object ID: 5837776
  7. Body Side Upper Rear Applique Bolt(2)»Remove
  8. Front Fender Upper Rear Molding- Left Side(1)»Remove

    9. Object ID: 5875924
  9. Headlamp Bolt(1)»Remove[5x]

    10. Object ID: 5875983
  10. Disconnect the electrical connector.
  11. Front Headlamp(1)»Remove
  12. Place a drain pan under the vehicle.
  13. Drain and properly dispose of the brake fluid in the master cylinder reservoir.
  14. Thoroughly clean the brake master cylinder reservoir and the brake master cylinder body to remove any dirt and debris.
  15. Electrical Connector@Brake System Control Module»Disconnect

    16. Object ID: 5918415

    Note: Due to similar connectors, label the brake fluid level indicator switch electrical connector and note the location and routing of the wire harness for proper installation.

  16. Electrical Connector@Brake Fluid Level Indicator Switch»Disconnect
  17. Brake Fluid Level Indicator Switch(1)»Remove

    18. Object ID: 5922185

    Warning: Do NOT clamp the brake master cylinder reservoir tube to stop the flow of brake fluid. Doing so could cause damage to the tube, degradation of braking performance, and potential loss of brakes. Failure to follow this warning may cause component damage or personal injury.

  18. Disconnect brake master cylinder reservoir hose (1) and cap the hose.

    19. Object ID: 5922186
  19. Brake Master Cylinder Reservoir Bracket Nut(1)»Remove[2x]

    20. Object ID: 5922187
  20. Brake Master Cylinder Reservoir- Upper(1)»Remove

    21. Object ID: 5922670
  21. Brake Master Cylinder Bolt(1)»Remove[2x]

    22. Object ID: 5922673
  22. Brake Master Cylinder Reservoir- Lower(1)»Remove and DISCARD

    23. Object ID: 5922672
  23. Brake Master Cylinder Reservoir Seal(1)»Remove and DISCARD[3x]

    24. Object ID: 5921465
  24. Remove the 2 rear brake front pipe nuts (1) and position the brake pipes aside.
  25. Remove the 2 front brake front pipe nuts (2) and position the brake pipes aside.

    26. Object ID: 5921468
  26. Brake Master Cylinder Adapter Nut(1)»Remove

    27. Object ID: 5921470
  27. Maneuver the brake master cylinder (1) out of the vehicle.
  28. Brake Master Cylinder Gasket(2)»Remove and DISCARD
  29. Clean any brake fluid from the underbody area and remove the drain pan from under the vehicle.

Installation Procedure


    Object ID: 5921470
  1. Brake Master Cylinder Gasket(2)»Install NEW
  2. Maneuver the brake master cylinder (1) into the vehicle.

    3. Object ID: 5921468

    Caution: Refer to Fastener Caution.

  3. Brake Master Cylinder Adapter Nut(1)»Install and tighten—Fastener Specifications

    4. Object ID: 5921465
  4. Rear Brake Front Pipe Nut(1)»Install and tighten[2x]—Fastener Specifications
  5. Front Brake Front Pipe Nut(2)»Install and tighten[2x]—Fastener Specifications

    6. Object ID: 5922672
  6. Lubricate the brake master cylinder reservoir seals (1) with GM approved brake fluid from a clean, sealed brake fluid container. Adhesives, Fluids, Lubricants, and Sealers
  7. Brake Master Cylinder Reservoir Seal(1)»Install NEW[3x]

    8. Object ID: 5922673
  8. Brake Master Cylinder Reservoir- Lower(1)»Install NEW

    9. Object ID: 5922670
  9. Brake Master Cylinder Bolt(1)»Install and tighten[2x]—Fastener Specifications

    10. Object ID: 5918415
  10. Brake Fluid Level Indicator Switch(1)»Install

    11. Note: Properly route the wire harness and brake fluid level indicator switch electrical connector as noted during removal.

  11. Electrical Connector@Brake Fluid Level Indicator Switch»Connect
  12. Electrical Connector@Brake System Control Module»Connect

    13. Object ID: 5922185
  13. Remove the cap and connect brake the master cylinder quick connect fitting (1).

    14. Object ID: 6410413
  14. Position the brake master cylinder reservoir - upper (1) , on to the 2 pins on the plenum panel bracket.

    15. Note: Necessary to fill the brake master cylinder reservoir and bleed the brake system before installing the brake master cylinder bracket upper due to lack of clearance underneath the cowl panel.

  15. Fill the brake master cylinder reservoir to the maximum-full level with GM approved brake fluid from a clean sealed brake fluid container. Brake Master Cylinder Reservoir Filling

    16. Object ID: 5918320
  16. Brake Pedal Nut(2)Install and tighten[4x]—Fastener Specifications
  17. If a NEW threaded component is being installed, loosen the adhesive using a metal pick or similar tool before proceeding. If threaded component is reused, prepare the threaded component using the following steps:
    1. Remove any loose cured adhesive from the external threads of the component using a lint free cloth.
    2. Thread the cleaned component into the internal mating threads and remove to loosen trapped cured adhesive.
    3. Remove loose debris from internal and external threads using compressed air.
    4. Apply liquid thread locking adhesive in a strip along half of the length of the external threads, starting at the tip, just prior to installation.Adhesives, Fluids, Lubricants, and Sealers
  18. Brake Pedal Push Rod Bolt(1)»Install and tighten—Fastener Specifications
  19. Connect the battery negative cable.Battery Negative Cable Disconnection and Connection
  20. Bleed the brake system.Hydraulic Brake System Bleeding
  21. Check for brake system leaks.

    22. Object ID: 5922187
  22. Brake Master Cylinder Bracket- Upper»Install

    23. Object ID: 5922186
  23. Brake Master Cylinder Reservoir Bracket Nut(1)»Install and tighten[2x]—Fastener Specifications

    24. Object ID: 5875983
  24. Front Headlamp(1)»Install
  25. Connect the electrical connector.

    26. Object ID: 5875924
  26. Headlamp Bolt(1)»Install and tighten[5x]—Fastener Specifications

    27. Object ID: 5837776
  27. Front Fender Upper Rear Molding- Left Side(1)»Install
  28. Body Side Upper Rear Applique Bolt(2)»Install and tighten—Fastener Specifications

    29. Object ID: 5840625
  29. With the aid of an assistant, install the fascia.(1)Front Bumper Fascia Removal and Installation
  30. Close the hood.