Sierra 3500 Denali 2WD V8-6.0L (2011)
corrosion, and/or brake dust, replace the brake master cylinder reservoir cap diaphragm. The diaphragm 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(R), GM P/N 12377967 (Canada P/N 992667) 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) (See: )Hydraulic Brake System Bleeding (Pressure) (See:
)Hydraulic Brake System Bleeding (Two-mode Hybrid) (See: ).
