How to Change a Wheel Cylinder

The hydraulic component in your vehicle's drum brake system is known as a wheel cylinder. It provides force to the brake shoes, causing them to contact the drum and slow the vehicle. Over time, the wheel cylinders in your drum brake system wear and begin to leak. Replacement of the leaking wheel cylinder will restore the proper function of the brake system. This repair project is well within the abilities of the home mechanic and can be completed in about 2 hours.

Instructions

1

Lift and support the vehicle with the floor jack and jack stands. Avoid working on the vehicle with only the floor jack supporting it's weight. Serious injury could result. Remove the wheel with the lug wrench, and place the wheel and lugnut out of the work area. Remove the drum. If the drum is stuck to the axle, a few blows with a hammer will break it loose.

2

Remove the two return springs that attach the brake shoes to the pivot pin at the top of the backing plate. Use the brake spring tool to do this. Avoid the use of diagonal cutters, pliers or screwdrivers to remove the springs, as these tools will damage the spring and cause nasty injuries to the hand.

3

Loosen the brake line with the line wrenches. Line wrenches are designed to spread the twisting force evenly around the nut and prevent damage to the brake line. Remove the wheel cylinder to backing plate bolts from the back side of the backing plate. Remove the brake line from the wheel cylinder and pull the cylinder out of the backing plate.

4

Insert the new wheel cylinder into the backing plate, and screw the brake line into the wheel cylinder. Do not tighten the fitting completely. Install and tighten the wheel cylinder to the backing plate bolts. Then tighten the brake line tightly with the line wrench. Reinstall the return springs and brake drum.

5

Bleed the brakes according to the manufacturer's bleeding sequence and procedure. This sequence and procedure varies by year, make and model, so consult your service manual for information specific to your vehicle.

6

Install the wheel, and lower the vehicle to the ground. Tighten the lugnuts one last time and test drive the vehicle to verify the repair.