How to Replace Drum Brakes
Maintaining your brakes helps ensure that your vehicle will come to a full stop when needed. While disc brakes are common, drum brakes are still found on some models. If your vehicle is one of those models, knowing when and how to replace drum brakes can help you stay safe and save money.
How Do Drum Brakes Work?
Drum brakes remain the standard braking force on most economy cars and are often found on the rear wheels of other models.
When you press on the brake pedal, pressurized pneumatic brake fluid is promptly pushed through the brake lines and into the brake cylinder. This causes a pair of springs in the cylinder to move against a piston at opposite ends of the cylinder. As each piston contacts the brake shoes, each shoe is forced against the drum. This enables the vehicle to stop.
Assemble Your Tools
Replacing drum brakes requires jacks or jack stands, chocks, a wire brush, a socket set and a drum brake adjustment tool. Safety glasses and protective gloves are strongly suggested. A can of aerosol brake cleaner and degreaser will also be necessary, as will the replacement parts, including brake shoes.
How to Replace Drum Brakes
With your car sufficiently elevated and chocked in a well-ventilated area, make sure the parking brake is disengaged before you remove the brake drum. From there, simply follow the steps outlined below. For more detailed information, refer to a maintenance manual, as the following steps are general instructions:
- Remove the drum. To get to the brake shoes, take the drum off. With the wheel set aside and the lug nuts located in a secure place, remove the retaining screws or clips, then slide the drum off. If it’s “frozen” in place, a light tap from a hammer should free it.
- Remove the brake shoes. The brake shoes are secured by hold-down and return springs.
- Clean and prepare. With the drum and shoes removed, inspect the remaining parts. Use the aerosol brake cleaner to remove brake dust. Use a wire brush when necessary to remove detritus build-up. Apply degreaser once you’re done.
- Install the brake components. The brake shoe pairs are composed of primary and secondary shoes. The secondary shoes are thinner and serve as the leading shoes. The primary shoes are the trailing ones toward the rear. Both are secured in place by springs and related hardware.
- Reinstall the brake drum. If the brake drum is fit for use, then reinstall it. Otherwise, replace this component. Slide it in place over the wheel studs, and secure the shoes onto the hub. Adjust the brakes with a specialized brake adjusting tool. Install the wheel, and secure it with the lug nuts. At this point, the brake shoes will contact the brake drum. Head over to the adjacent wheel and give it the same treatment.
- Once the vehicle is back on firm ground, take it for a ride. Lightly press the brake pedal to ensure it feels firm, with no squeaks or squeals present. Over time, the brake shoes will seat, but your braking should feel normal now. If not, the brakes may need bleeding or adjustment.
When you replace your vehicle’s drum brakes, be sure to change them out in pairs for even wear and optimum control.
Check out all the brake system products available on NAPA Online, or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on drum brakes, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photo courtesy of Wikimedia Commons.
Matthew C. Keegan View All
Matt Keegan has maintained his love for cars ever since his father taught him kicking tires can be one way to uncover a problem with a vehicle’s suspension system. He since moved on to learn a few things about coefficient of drag, G-forces, toe-heel shifting, and how to work the crazy infotainment system in some random weekly driver. Matt is a member of the Washington Automotive Press Association and is a contributor to various print and online media sources.
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