GM 19371352
Brake Booster

Two distinct fluids operate independently in hydraulic brake systems since power steering fluid resides in the hydraulic Brake Booster system and brake fluid remains within the master cylinder and brake pipes. This mandates using compatible brake system fluids to avert brake seal damage. The first step to remove the hydraulic Brake Booster begins with disconnecting the negative Battery Cable followed by activating the parking brake. The procedure starts by disconnecting the inlet hose and steering gear as well as return hoses from the booster assembly. Afterward master cylinder nuts must be removed followed by the master cylinder and wiring harness bracket and stoplamp switch and Pushrod. The procedure continues with the removal of booster to bulkhead nuts while the booster assembly and included gasket also need extraction. First install the gasket and afterward install the booster assembly. Start by installing the bulkhead nuts to their specific torque of 36 nm (26 ft. Lbs.) before mounting the stoplamp switch and Pushrod. The master cylinder and its bracket follow in the assembly process and receive a torque of 30 nm (20 ft. Lbs.). Proceed by tightening master cylinder nuts to 30 nm (20 ft. Lbs.), reattaching the return hose as well as steering gear and inlet hoses. Then connect the negative Battery Cable. Follow the bleeding procedure when needed for the hydraulic booster system.

The hydraulic Brake Booster system needs power steering fluid as its base fluid but the master cylinder and brake pipes function with brake fluid so choosing suitable fluid becomes essential for preventing seal leakage. When checking or adding fluid in the hydraulic booster system use the same procedure as for power steering fluid. Follow power steering system procedures to bleed and flush the hydraulic booster system. Start by applying the parking brake before disconnecting the inlet hose and steering gear along with the return hoses from the booster assembly. When replacing a braking system start by removing the master cylinder according to procedures for vacuum boost or hydraulic boost then unfasten the stoplamp switch and Pushrod followed by booster to bulkhead nuts before separating the booster assembly and gasket. To install begin with the gasket positioning followed by the booster assembly fitment then torque the booster bulkhead nuts to 36 n.m (26 lb ft). Begin with the stoplamp switch and Pushrod installation followed by the master cylinder (Master Cylinder Replacement) and then connect the return hose and steering gear along with the inlet hoses. The final step includes bleeding the hydraulic booster system.

First, take out the negative Battery Cable and then engage the park brake before replacing the vacuum Brake Booster. Remove the nuts that hold the master cylinder and then pull out the master cylinder and bracket. Start by removing the hose and the retainer, then the stoplamp switch and Pushrod and finish by taking out the assembly and the gasket by removing four nuts. The first step is to place the gasket, then the booster assembly and tighten the four nuts to 36 nm (26 ft. Lbs.). After that, fit the Pushrod, stoplamp switch and retainer and finally the vacuum hose. After checking the booster Pushrod, put in the master cylinder and bracket while fastening the master cylinder nuts with 30 nm (20 ft. Lbs.) torque. After that, let go of the park brake and join the negative cable to the battery again.

One should start Brake Booster (3500HD) replacement by taking out the negative Battery Cable while also applying the parking brake. The booster assembly requires disconnecting its inlet hose and steering gear as well as its return hoses. First remove master cylinder nuts and then take out the master cylinder followed by the wiring harness bracket and spacer from the booster assembly. You must begin your installation process by taking out the stoplamp switch followed by removing the Pushrod from the brake pedal pin then the booster nuts because these parts precede the booster assembly and its gasket removal. Begin by installing the gasket followed by the booster assembly then screw the booster nuts to 36 nm (26 ft. Lbs.). Install the Pushrod onto the brake pedal pin after which install the stoplamp switch. Begin the installation by adding the spacer followed by the wiring harness bracket and master cylinder onto the booster assembly using torque of 30 nm (20 ft. Lbs.) to the master cylinder nuts. The return hose and steering gear as well as inlet hoses need to be connected and then the negative Battery Cable must be reconnected and finally the hydraulic booster system needs bleeding.