Brake Drum & Shoe Kits
Brake Drum & Shoe Kits at 1A Auto
What are brake drums and shoes, and where are they located?
Brake drums and shoes are a major component of some vehicle's braking systems. A drum braking system consists of brake drums, shoes, backing plates, and wheel cylinders. Like many brake rotors, automotive brake drums are usually made from cast iron. They bolt on to the wheel hubs or axles, and they spin at the same rate as the wheels. All of the other braking components are confined to the inside of the drum.
When you pump the brakes, hydraulic pressure is transmitted to the wheel cylinder, causing the pistons to extend. The brake shoes then press out to squeeze the drum, which in turn stops your vehicle. Brake shoes are curved and made of steel with a brake block lining the exterior to create the friction needed to stop.
At one point in time, drum brakes were the standard for all vehicles. Rear drum brakes are still found on many vehicles today. If a car or truck is only equipped with brake drums, then it will have one drum for each wheel. If a car or truck only has brake drums only in the rear of the vehicle, then the vehicle will have two front brake rotors and two rear brake drums.
How do I know if my brake drums and shoes need to be replaced?
Brake shoes will usually last longer than the brake pads in a disc brake system do, but they do not dissipate heat as well. As heat builds within the brake drum, the brakes become less effective. There are a couple ways to tell if brake drums are not working properly. You might hear screeching each time you press the brakes, or, even worse, grinding-both of which may indicate a needed replacement of brake shoes. The emergency brake might also not hold as strongly as it used to, and this might be an indication that shoes need replacing.
One of the best ways to inspect the brake drum components is to look at them. If the shoes are exceptionally thin or almost worn down to the metal, they should definitely be replaced. Brake drums can be resurfaced or machined as long as there is enough material to do so. All brake drums have a discard diameter determined by the manufacturer, which is the maximum inside diameter the drum can be machined to before they are deemed unsafe. You should measure the inside diameter with a micrometer at multiple points to ensure the drum is not uneven or out of round, and is within specification.
It is recommended to measure the drums every time you inspect the brakes or replace the brake shoes, as well as to regularly inspect the brake drum assembly for any signs of cracking, rust, corrosion, or uneven friction. At one time it was very common to resurface brake drums, but today it is often more cost effective to replace the drums rather than machine them.
Can I replace the brake drums and shoes myself?
Replacing a brake drum and shoes can be a physically challenging task, but, if you are handy enough to inspect the brake drums, then you should have a good shot at replacing them. You'll need a pair of pliers and possibly a screwdriver. The process for changing brake drum components can vary depending on the manufacturer's design, but the repair is generally the same. We recommend wearing eye protection when removing the springs to prevent any potential mishap. Vise-grip pliers can make spring removal easier.
The first step is to pry off the top spring from its clip on the brake shoe. Then pull it off the second brake shoe. Pull back on the shoe to remove the adjuster. Remove the retaining clip from behind the brake shoe, and then pry the bottom spring from the shoe. You might have to remove a clip from the brake shoe that keeps the emergency brake cable attached.
Before reinstallation, it's a good idea to clean any rust off the drum, the backing plates, and the rest of the assembly with brake cleaner and a wire brush. Then insert a washer onto the emergency brake, press the shoe into place, insert the top washer onto the shoe, and tighten the clip. Insert the brake shoe into place, press the pin, spring, and spring caps into place, and turn it to lock the spring and shoe in place. Repeat the process for the other side. After the shoes are in place, insert the brake adjuster into place, press the clip into the adjuster, and then pull the spring into the new brake shoe. Then attach and pull lower spring into the shoe. Then reattach the drum and wheel.