Master Cylinder Reservoir Replacement (J55)

Master Cylinder Reservoir Replacement (J55)
Warning: Refer to Brake Fluid Irritant Warning (Brake Fluid Irritant Warning).


Caution: Refer to Brake Fluid Effects on Paint and Electrical Components Caution (Vehicle Damage Warnings).

Removal Procedure

1. Remove the master cylinder from the vehicle. Refer to Master Cylinder Replacement (Master Cylinder Replacement).
2. Disconnect the electrical connector from the fluid level sensor.
3. Remove the master cylinder fluid level sensor. Refer to Brake Fluid Level Indicator Switch Replacement (Service and Repair).
4. Drain the brake fluid from the master cylinder reservoir.




5. Carefully tap back the retaining pins until clear of master cylinder reservoir.




6. Remove the master cylinder reservoir from the master cylinder.
7. Remove the seals from the master cylinder reservoir.

Installation Procedure

1. Inspect the master cylinder reservoir for cracks or deformities. If found, replace the reservoir.
2. Clean the reservoir with clean denatures alcohol or equivalent.
3. Dry the master cylinder reservoir with non-lubricated, filtered air.




4. Lubricate the new seals and the reservoir bayonets with GM approved brake fluid from a clean, sealed brake fluid container. Refer to Fluid and Lubricant Recommendations (Service Intervals).
5. Install the seals, making sure they are fully seated.
6. Install the reservoir onto the master cylinder by pressing straight down by hand until the pins holes are aligned.
7. Press straight down by hand until pin holes are aligned.




8. Carefully tap in the master cylinder reservoir retaining pins to secure the reservoir.
9. Fill the master cylinder reservoir. Refer to Master Cylinder Reservoir Filling (Master Cylinder Reservoir Filling).
10. Install the master cylinder fluid level sensor. Refer to Brake Fluid Level Indicator Switch Replacement (Service and Repair).
11. Connect the electrical connector to fluid sensor.
12. Install the master cylinder. Refer to Master Cylinder Replacement (Master Cylinder Replacement).