When learning how to change drum brakes, it helps to know that there is a multitude of rear drum brake configurations. The differences are primarily in the return spring locations. The operation of the rear drum brakes remains the same on all vehicles regardless of the spring locations. That being the case, once the operation is understood it will be easy to replace rear drum brakes on any vehicle.
When the wheels and brake drum are removed the brakes will be exposed. You will find one brake shoe on the left and one on the right side. These are quarter moon shaped steel with asbestos pads either glued or riveted onto the steel body. At the very top center of the brake assembly there is a fulcrum pin. The return springs are attached to the brake shoes and to this fulcrum.
The top of the brake shoes also contacts this fulcrum. Directly below this, there is a wheel cylinder in between both brake shoes. When the brakes are applied, high-pressure brake fluid enters the wheel cylinder and forces the two pistons outward, in turn spreading the brake shoes apart. Once the pressure is released, the return springs pull the brake shoes back in to the released position.
Directly below the wheel cylinder there is a spreader bar that fits between both shoes. This is just to keep the shoes straight so they can't twist from the spring pressure. On the side of each brake shoe steel body, just about centered on the shoe, there is a pin running from the back of the brake backing plate, through the brake shoe and held in place with a coil spring and a small metal cap. The pin secures the brake shoe to the brake backing plate.
At the bottom, center there is a brake adjuster used to adjust the brakes by spreading them apart as the wheel is turned. The rear shoe will always have the emergency brake lever attached to the rear shoe metal body. The last piece is the retaining spring on the bottom connected to both shoes used to keep the bottom of both shoes against the bottom pin.
Tools required to change rear drum brakes:
Raise and support the vehicle on jack stands. Remove the wheel/tire assembly. Hit the brake drum around the face with the hammer to loosen it up enough to pull it off. It gets rusted around the center of the axle.
Remove the upper springs with the spring removal tool. Lay them on the floor just the way they came off to make installation easier. Remove the emergency brake cable that was under the springs.
Take the spreader bar out while paying attention to its orientation. Remove the brake hold-down pin on both shoes using the spring cap removal tool. Remove the lower brake adjuster and spring.
Remove the emergency brake arm from the backside of the rear brake shoe. Before installing the new brake shoes, lay the shoes on the floor and look for the shoe that has the brake material farther down from the top than the other. The low shoe must always be installed toward the front of the car.
Attach the emergency brake lever to the inside of the rear shoe. Attach the small spring followed by the brake adjuster to the bottom of both shoes. Lift the shoes up into place and install the retaining pin through the back of the backing plate, through the hole provided in the shoe. Install the coil spring and cap. Install the spreader bar.
Install the emergency brake cable followed by the brake return springs. Adjust the brake adjuster to the point that when the brake drum is installed, the shoes just barely touch the drum. When the drum is rotated by hand, there should be just a little bit of pressure--it should turn easily, with just a little bit of a scraping sound. It may take three or four tries to get the brakes adjusted to the right point.
Changing disc brakes gets easier each time you do it. But you can skip to the advanced class just by following a few basic tips.
Do you know how to bleed ABS brakes? You can't bleed the entire system without specialized equipment, but you can take care of some minor bleeding on your own.