How to Repair a Brake Cylinder

What You'll Need
Tire iron to remove tire
Car jack with stand
Drain pan for brake fluid
Brake drum puller tool
Brake spring remover
Brake shoe remover
Line wrench
New brake cylinder

There are certain elementary steps that need to be observed to repair the brake cylinder of the car. The brake cylinder of an automobile is the central storage of brake fluid. The piston, fitted into the central bore of the cylinder, is pushed by pressing the brake pedal resulting into a hydraulic pressure in the fluid. This hydraulic pressure stops the automobile by transferring this pressure into the brake system. Many things can cause damage to the brake cylinder, however. Most common is wear and tear in the long run. To repair the cylinder, certain specific tools are required and a keen observation to understand the automotive parts arrangement. This article will look at a rear drum brake system. However, a vehicle using a disc brake and caliper has a similar theory behind it. The only difference being is that to get to the piston, you only need to remove the caliper from the disc rather than disassemble an entire drum brake. In most cases it is advised to replace the entire brake cylinder rather than repair a faulty one.

Step 1 – Removing the Tire

Use the tire iron to loosen the screws on the wheel in which the brake cylinder has to be replaced. When nuts on the wheel are loose enough then use the car jack to put the car on the jack stand. Now remove the nuts from the wheel, remove the wheel and put everything on one side.

Step 2 – Remove the Brake Drum

The outer brake drum is visible once the wheel is removed from the axle. Align the access orifice of the drum with the screw for adjustment on the inner side by rotating the drum. Use a screwdriver to loosen up the screw so that the drum is retracted. If this does not work then use a hammer to hit it out of its position, but don’t hit too hard on the drum. If this doesn’t work then use the brake drum puller to take out the brake drum.

Step 3 – Identify Components

One can see smaller parts of the brake drum once it is removed. There are two brake shoes with springs and a wheel cylinder within. The other important parts include emergency brake arm and a return spring for the brake shoe.

Step 4 – Open Brake Shoes

To access the wheel cylinder remove brake shoes or replace them if they are highly worn out. Check for leakage from wheel cylinder, if there exists any then replace it immediately. Use a brake spring remover to remove the return springs from the brake shoe. Now with the brake shoe remover, remove one of the shoes while leaving the other undisturbed for reference.

Step 5 – Replace Brake Cylinder

Use line wrench to dislodge the wheel assembly from the brake line. Keep the drain pan beneath the brake cylinder for overflowing fluid. Loosen the nuts from the cylinder and pull it out of place. Install the new cylinder using the reverse process.

Step 6 – Reassemble the Brake Line

Use the line wrench to re-attach the brake line assembly. Put back the wheel assembly in its place as it was earlier.

Step 7 – Replace the Brake Shoes and Tire

Put back the retainer and return springs with the brake shoes. Depress the brake pedal a few times to push any air out of the system. Place the wheel back on the car and drive slowly in an open area to check if everything is working fine.