Troubleshooting: Wheel Cylinders
Wheel Cylinders Fitment Instructions
Attention: This is a generic guide. Please consult your vehicle service booklet specific fitment instructions.
Begin with the vehicle lifted enough to access the brakes while using jack stands for safety and wearing protective eyewear and gloves. .
CAUTION: Brake fluid is corrosive, use caution when handling.
- Remove wheel and brake shoes. After the brake shoes have been removed from the backing plate, the wheel cylinder is now ready to be replaced.
- When replacing the wheel cylinder, use a line wrench to avoid damage to the fitting while removing the brake line. (Note: Brake fluid will be present.)
- Once the brake line has been removed, brake fluid will drip out of the line until the brake master cylinder is empty, a vacuum cap should be used to prevent the loss of fluid from the master.
- Next, use a wrench or socket to remove the wheel cylinder mounting bolts. (Note: Some wheel cylinders are held in place by a snap ring.)
- After removing the wheel cylinder mounting bolts, grasp the unit and separate it from the backing plate.
- Once the old wheel cylinder has been matched up to the new unit, insert it into the backing plate and secure the mounting bolts.
- Then, using a wrench or ratchet tighten the wheel cylinder mounting bolts.
- After tightening the wheel cylinder mounting bolts, remove the cap which was previously installed and hand thread the brake line fitting into the cylinder to prevent cross threading.
- Once the fitting has been threaded by hand, use a line wrench to tighten the brake line.
- Then, use a small screwdriver to remove the bleeder cap, this will allow the brake fluid to be bled in later steps.
- After the wheel has been installed and lug nuts tightened, clean the top of the brake master cylinder using a shop towel, then loosen and remove the lid.
- Using a sealed container of brake fluid, top off the brake master cylinder with fluid.
- Once the fluid level has be added to, reinstall and tighten the reservoir cap.
- Have a helper press the brake pedal down and hold. (Note: Do not pump brake pedal.)
- While the brake pedal is being held down, open the bleeder screw on the rear of the wheel cylinder, fluid will begin to flow out of the valve, once the fluid has stopped close the valve and slowly release the brake pedal, repeat this operation until no air bubbles are observed.
- Once the bleeding process is complete, recheck the fluid level inside the master cylinder reservoir and add as needed to obtain the proper level. Once both wheels have been completed and while holding the brake pedal down, activate the parking brake lever several times to set and adjust the shoes against the drums.
DO NOT MOVE THE VEHICLE UNLESS NORMAL BRAKE PEDAL OPERATION IS PRESENT!
A fluid leak can cause the brake shoes to grab or lock up, and ultimately fail completely. (Note: Your front brake system will still work, with a slightly lower brake pedal position and diminished brake operation.)
If the shoes are saturated with brake fluid, replacement is needed.
If the brake pedal is spongy air is in the system and bleeding will need to be redone.
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