Removing and installing the cap is straightforward. Be sure to thoroughly clean around the reservoir cap before removing it to avoid getting dirt into the reservoir. Then remove the cap with a diaphragm.

The fluid level sensor is serviced only by replacing the reservoir.

1. Disconnect the electrical connector from the fluid level sensor.
2. Drain the brake fluid from the master cylinder reservoir.



3. Tap back pins until clear of reservoir. Be careful not to damage the reservoir or the master cylinder. If needed, loosen or remove the strut cross bar for access.
4. Remove the reservoir.
5. Remove the seals.
6. Inspect the reservoir for cracks or deformities. If found, replace the reservoir.
7. Clean the reservoir with clean denatured alcohol. Dry with unlubricated compressed air.

1. Lubricate the new seals and reservoir bayonets with clean brake fluid.
2. Install the seals, making sure they are fully seated.



3. Install the reservoir onto the master cylinder by pressing straight down by hand until the pin holes are aligned.
4. Tap in the pins to retain the reservoir. Be careful not to damage the reservoir or master cylinder. If the strut cross bar had been loosened or removed, reinstall it.
5. Fill the master cylinder reservoir to the full level mark using only Delco Supreme II (GM P/N 12377967) Brake Fluid, or equivalent DOT-3 brake fluid, as specified in Maintenance and Lubrication.
6. Connect the electrical connector to the fluid level sensor.
7. Bleed the hydraulic system. Refer to Hydraulic Brake System Bleeding .
8. Recheck the fluid level in the reservoir.