WHEEL CYLINDER

REMOVAL: Block the brake pedal in the released position to prevent its being moved accidentally while the cylinder is off, thus avoiding the loss of brake fluid.

In our case this is a complete teardown so there is no need to perform this next procedure. The following instruction is offered if only the wheel cylinder is in need of service.

Jack up the vehicle and remove the wheel and brake drum. Unfasten the brake line or hose from the wheel cylinder connection. Unhook the brake shoe retracting spring to permit the shoes to be moved away from the cylinder.

At this point, if step bore cylinders are used, note carefully in which direction the larger bore is facing. On some vehicles, the larger bore faces the rear while on others it faces the front. Pay close attention here!

DISASSEMBLY: The above is an exploded view of a typical wheel cylinder used with Bendix and Lockheed brakes.

To disassemble, remove the end covers and push out the pistons, rubber cups and spring. Wash all parts in Berryman's Brake Cleaner or clean alcohol, but before doing so, wash your hands with soap and water to avoid the possibility of mineral oil or gasoline products from coming in contact with the parts during assembly.

INSPECTION: Examine the cylinder walls. If found to be scored or rusted, the cylinder must be reconditioned by honing.  A hone of the proper size should be placed in the chuck of an electric or battery drill. Work the hone back and forth a few times, then inspect the cylinder to see if the wall is cleaned up. Do not hone any more than is required to remove scores and smooth up the cylinder.

Clearance between the pistons and cylinder wall should be from .002 to .004" when checked with a feeler gauge.  If the clearance is more than .004" and new pistons will not  provide the correct clearance, a new housing will have to be installed.  Always use new rubber parts when reconditioning a cylinder. Rubber parts which are swollen or damaged will seriously impair the proper function of the brakes. Repair kits are available which contain all parts usually required for re-conditioning wheel cylinders.

REASSEMBLE & REPLACEMENT: Dip pistons and rubber cups in brake fluid. Place the spring in the center of the housing, the rubber cups at each end of the spring, with their cupped sides to the spring and the flat face of the cups flush with the piston. (Or. step bore cylinders the spring is tapered, therefore, be sure to place the small tapered end against the smaller piston.) Replace the end covers.