Power Brake Booster

DESCRIPTION






The power brake booster mounts on the engine compartment side of the dash panel. It is connected to the brake pedal by the input (push) rod. The master cylinder is bolted to the front of the power brake vacuum booster assembly. A vacuum line connects the power brake booster to the intake manifold.
All vehicles use a 270 mm single diaphragm vacuum power brake booster.
All vehicles use a common power brake booster, except models equipped with All-Wheel-Drive (AWD). Differences between the two are internal. Service is the same on all boosters.






The power brake booster can be identified by the tag attached to the body of the booster. This tag contains the production part number, the date it was built, and who the manufacturer of the power brake booster is.

NOTE: The power brake booster assembly is not a repairable component and must be replaced as a complete assembly if it is found to be faulty in any way. The check valve located on the power brake booster is not repairable, but it can be replaced separately from the power brake booster.

The different engine combinations used in this vehicle require different vacuum hose routings to the power brake booster. All vacuum hoses must be routed from the engine to the power brake booster without kinks or excessively tight bends.

OPERATION
The power brake booster reduces the amount of force required by the driver to obtain the necessary hydraulic pressure to stop a vehicle.
The power brake booster is vacuum operated. The vacuum is supplied from the intake manifold on the engine through a vacuum hose and the power brake booster check valve.
As the brake pedal is depressed, the power brake booster's input rod moves forward. This opens and closes valves in the power booster allowing atmospheric pressure to enter on one side of a diaphragm. Engine vacuum is always present on the other side. This difference in pressure forces the output rod of the power brake booster out against the primary piston of the master cylinder. As the pistons in the master cylinder move forward this creates the hydraulic pressure in the brake system.