GM Service Manual Online
For 1990-2009 cars only

These tests will not find all master cylinder malfunctions. If the cause is not found with these tests, refer to Hydraulic Brake Diagnostic System Check .

    • Check for a cracked casting or brake fluid leaks around the master cylinder.
        A leak will have at least one drop of fluid. A damp condition is normal.
    • Check the pedal linkage for binding and for incorrect pushrod length.
    • Disassemble the master cylinder if there is improper brake pedal travel or brake pedal binding. Refer to Master Cylinder Overhaul .
    • Check the master cylinder for swollen or elongated primary piston seals.
        If you find swollen seals, replace the seals. Refer to Seal Leak Diagnosis .