What happens when you replace a brake drum
A brake drum is the metal cylinder that sits inside your wheel and holds the brake shoes. When you press the brake pedal, the shoes press outward against the inside of the drum to slow the wheel. Over time, the drum wears thin, develops cracks, or becomes so scored (scratched) that the shoes can no longer grip it evenly. At that point, the drum must come off and either be resurfaced (machined smooth) or replaced with a new one.
Replacing a brake drum takes two to four hours per axle if you have basic mechanical skills and the right tools. The job involves removing the wheel, taking off the brake assembly, sliding the old drum off, and installing a new one. You'll also need to inspect and likely replace the brake shoes at the same time, since worn shoes and a worn drum usually arrive together.
This is a job you can do yourself if you're comfortable working under a vehicle and have access to a jack, jack stands, and a socket set. If you're not confident, a shop will charge between $300 and $800 per axle depending on your vehicle and whether the shoes need replacement too.
Key Takeaways
- Brake drums wear out from friction and must be replaced when they're too thin to machine or too damaged to grip the shoes evenly.
- You'll need a jack, jack stands, a socket set, a drum puller tool (sometimes), and new brake shoes to do the job yourself.
- The process involves removing the wheel, disconnecting the brake assembly, sliding off the old drum, and bolting on the new one.
- After installation, you must bleed the brake system if you disturbed any brake lines, and test the brakes before driving.
- If the drum is stuck, a drum puller or penetrating oil can free it, but forcing it risks damaging the wheel hub.
Gather your tools and materials before you start
You'll need a floor jack and at least two jack stands rated for your vehicle's weight. Never work under a car supported only by a jack. You also need a socket set (metric or SAE depending on your vehicle), a wrench set, and brake fluid (the type your vehicle uses—check your owner's manual or the cap on the master cylinder).
A drum puller is a three-legged tool that bolts to the drum and pulls it straight off the hub. Many drums come off by hand once the wheel is removed, but a stuck drum will need this tool. You can rent one from an auto parts store for $15 to $30 per day. You'll also want new brake shoes (the friction material inside the drum), a brake spring tool (a small hooked tool for removing and installing the springs that hold the shoes), and brake cleaner to remove dust and debris.
Wear safety glasses and work gloves. Brake dust contains asbestos in older vehicles, so avoid breathing it and wash your hands after the job. If you're unsure about any step, stop and consult your vehicle's service manual or a shop—brake work done wrong is dangerous.
Remove the wheel and access the brake drum
Park on a level surface, engage the parking brake, and loosen the lug nuts on the wheel with the vehicle still on the ground. This prevents the wheel from spinning when you lift. Then use the floor jack to lift the vehicle, place jack stands under the frame (never under plastic trim or suspension parts), and lower the vehicle onto the stands. Remove the lug nuts completely and take off the wheel.
You now see the brake drum—a hollow metal cylinder bolted or pressed onto the wheel hub. If your vehicle has a dust cap covering the center, pry it off gently with a flathead screwdriver. Look for a small rubber plug on the back of the drum; this is the access hole for the self-adjuster. You may need to reach through it with a screwdriver to release the adjuster before the drum will come off.
Try pulling the drum straight toward you by hand. If it slides off easily, great. If it's stuck, spray penetrating oil (like WD-40 or PB Blaster) around the edge where the drum meets the hub and let it soak for 15 minutes. Then try again. If it still won't budge, bolt the drum puller to the drum and turn the center bolt slowly to pull it straight off. Do not hit the drum with a hammer or pry it sideways—this can damage the hub.
Disconnect and remove the brake assembly
Once the drum is off, you see the brake shoes (curved friction material) held in place by springs and a wheel cylinder (a small hydraulic piston). Before you touch anything, take a photo with your phone so you remember how it goes back together. The springs and clips are straightforward to lose or install wrong.
Use the brake spring tool to unhook the return springs (the large springs pulling the shoes apart). Then remove the hold-down clips and springs that pin each shoe to the backing plate. Slide the shoes out carefully. If you're reusing the old shoes, set them aside. If you're installing new ones, you can discard the old ones—they're worn out anyway.
Inspect the wheel cylinder for leaks. If brake fluid is weeping from the seams, the cylinder must be replaced. This is a separate job; if you spot this, consider taking the vehicle to a shop. If the cylinder is dry, leave it in place. Clean the backing plate (the metal surface the shoes sit on) with brake cleaner and a rag to remove all dust and debris.
Install new brake shoes and reassemble
New brake shoes come as a kit with springs and clips already attached or as separate pieces. Follow the instructions that come with the kit. Generally, you'll install the new shoes on the backing plate, hook the return springs back on, and find the hold-down clips. The shoes should sit centered on the backing plate with even gaps on both sides.
Adjust the self-adjuster (the mechanism inside the drum that keeps the shoes the right distance from the drum as they wear). This is usually a star wheel or cam inside the backing plate. Turn it until the shoes are snug against the drum, then back it off slightly so the drum spins freely with a little resistance. This prevents the brakes from dragging.
Slide the new brake drum onto the hub. If it doesn't slide on smoothly, the shoes may be too tight. Back off the adjuster a bit more and try again. Once the drum is on, bolt it down finger-tight, then use a socket wrench to tighten the bolts in a star pattern (opposite sides alternately) to may support even pressure. Tighten to the torque specification in your service manual, typically 35 to 50 foot-pounds.
Reinstall the wheel and bleed the brakes
Put the wheel back on and hand-tighten the lug nuts. Lower the vehicle off the jack stands by slowly raising the floor jack until the tire touches the ground, then remove the jack stands and lower the vehicle completely. Now tighten the lug nuts in a star pattern with a socket wrench to the specification in your manual, usually 80 to 100 foot-pounds for most cars.
If you disconnected any brake lines during the job, you must bleed the brakes to remove air from the system. Air in the brake lines makes the pedal feel spongy and reduces stopping power. Have a helper sit in the driver's seat while you open the bleeder valve (a small bolt on the wheel cylinder) and pump the brake pedal. Brake fluid will flow out; catch it in a container. Close the valve, pump again, and repeat until no air bubbles come out. Do this at all four wheels, starting with the wheel farthest from the master cylinder.
If you didn't disconnect any lines, you can skip bleeding. However, pump the brake pedal several times with the engine off to build pressure, then start the engine and test the brakes in a safe area before driving normally. The pedal should feel firm and responsive, not soft or low.
Common problems and how to fix them
If the drum won't come off after soaking with penetrating oil, do not force it. A stuck drum usually means rust has bonded it to the hub. Soak it longer (overnight if possible), or use a drum puller. If you don't have access to a puller, this is the point to take the vehicle to a shop rather than risk damaging the hub.
If the brakes feel soft or the pedal goes to the floor after you finish, air is trapped in the brake lines. Bleed the system again, starting with the wheel closest to the master cylinder this time. If the problem persists, you may have a leak in a line or the wheel cylinder. Inspect all connections for fluid weeping and tighten or replace as needed.
If the brakes drag (the wheel is hard to turn by hand even with the parking brake off), the shoes are too tight against the drum. Back off the self-adjuster and spin the wheel to confirm it turns freely. If dragging continues, the adjuster may be stuck or the shoes may be installed backward. Remove the drum and check the shoe orientation against your photo.
Frequently Asked Questions
Can I replace just the drum without replacing the brake shoes?
Technically yes, but it's not recommended. Worn shoes and a worn drum usually need replacement together. Installing a new drum with old, thin shoes will cause uneven braking and the new drum will wear quickly. Most shops replace both at the same time to avoid a second job in a few months.
How do I know if my brake drum needs replacement?
You'll hear grinding or squealing when braking, feel a pulsing or soft pedal, or notice the brake warning light on the dashboard. A shop can measure the drum's thickness with a micrometer; if it's below the minimum thickness stamped on the drum itself, it must be replaced. Cracks or deep scoring also mean replacement.
What's the difference between resurfacing and replacing a drum?
Resurfacing (machining) removes a thin layer from the inside of the drum to smooth out scoring and restore the braking surface. It's cheaper than replacement but only works if the drum is thick enough. If the drum is already at minimum thickness, machining would make it too thin and unsafe, so replacement is the only option.
Do I need to bleed the brakes if I only replaced the drum?
Only if you disconnected a brake line or the wheel cylinder. If you straightforward removed the drum without touching any hydraulic parts, bleeding is not necessary. However, pump the pedal several times to restore pressure before driving.
Why is my new drum rusted already?
New drums come with a light coat of oil to prevent rust during shipping and storage. This is normal. Wipe it off with a clean rag before installation. Once the drum is on the vehicle and exposed to moisture, light surface rust may form over time, but this doesn't affect braking. If heavy rust develops inside the drum, the vehicle is spending too much time in wet conditions and may need undercoating.