Ford Mid-Size Cars 1971-1985 Repair Guide

Wheel Cylinders



Brake shoes may contain asbestos, which has been determined to be a cancer causing agent. Never clean the brake surface with compressed air! Avoid inhaling any dust from any brake surface! When cleaning brake surfaces, use a commercially available brake cleaning fluid.

  1. Remove the brake shoes.
  3. Loosen the brake line on the rear of the cylinder but do not pull the line away from the cylinder or it may bend.
  5. Remove the bolts and lockwashers which attach the wheel cylinder to the backing plate and remove the cylinder.

To install:
  1. Position the new wheel cylinder on the backing plate and install the cylinder attaching bolts and lockwashers.
  3. Attach the metal brake line.
  5. Install the brakes. Bleed and adjust the brake system.


See Figure 1

Since the travel of the pistons in the wheel cylinder changes when new brake shoes are installed, it is possible for previously good wheel cylinders to start leaking after new brakes are installed. Therefore, to save yourself the expense of having to replace new brakes which become saturated with brake fluid and the aggravation of having to take everything apart again, it is strongly recommended that wheel cylinders be rebuilt every time new brake shoes are installed. This is especially true on high mileage cars.

  1. Remove the brakes.
  3. Remove the wheel cylinder from the vehicle and place on a clean well lighted table.
  5. Remove the boots from the ends of the wheel cylinders.
  7. Push one piston toward the center of the cylinder to force the opposite piston and cup out of the other end of the cylinder. Reach in the open end of the cylinder and push the spring, cup, and piston out of the cylinder.
  9. Remove the bleeder screw from the rear of the cylinder on the back of the backing plate.
  11. Inspect the inside of the wheel cylinder. If it is scored in any way, the cylinder must be honed with a wheel cylinder hone or fine emery paper, and finished with crocus cloth if emery paper is used. If the inside of the cylinder is excessively worn, the cylinder will have to be replaced, as only 0.003 in. (0.076mm) of material can be removed from the cylinder walls. When honing or cleaning the wheel cylinders, keep a small amount of brake fluid in the cylinder to serve as a lubricant.
  13. Clean any foreign matter from the pistons. The side of the pistons must be smooth for the wheel cylinders to operate properly.
  15. Clean the cylinder bore with alcohol and a lint-free rag. Pull the rag through the bore several times to remove all foreign matter and dry the cylinder.
  17. Install the bleeder screw and the return spring in the cylinder.
  19. Coat new cylinder cups with new brake fluid and install them in the cylinder. Make sure that they are square in the bore or they will leak.
  21. Install the pistons in the cylinder after coating them with new brake fluid.
  23. Coat the insides of the boots with new brake fluid and install them in the cylinder. Install the brakes.

Click image to see an enlarged view

Fig. Fig. 1: A disassembled wheel cylinder