What drum brakes are and why you might replace them
Drum brakes are a braking system where friction material called brake shoes press against the inside of a rotating drum to slow your vehicle. They're commonly found on the rear wheels of cars and trucks, though some older vehicles have them on all four wheels. Over time, the friction material wears down and the drums themselves can become scored or warped, reducing braking power and sometimes causing noise or a soft brake pedal.
Replacing drum brakes involves removing the wheel and drum, taking out the old brake shoes and hardware, and installing new shoes and springs. The job requires basic hand tools, some mechanical knowledge, and patience — it typically takes two to four hours per wheel if you're working alone for the first time. Many people do this work in a driveway or garage, though a lift makes access easier.
Key Takeaways
- Drum brake replacement requires removing the wheel, drum, and old brake shoes, then installing new shoes, springs, and hardware in the correct order.
- You'll need a jack, jack stands, a drum puller or slide hammer if the drum is stuck, a brake spring tool, and basic wrenches — specialty tools are not expensive.
- The brake shoe assembly has a specific layout with return springs, hold-down springs, and an adjuster; photographing the old assembly before disassembly prevents confusion during reassembly.
- Brake fluid does not need to be bled from the system when replacing drum brakes, unlike disc brake pad changes, which simplifies the job.
- If the drum is cracked, severely scored, or won't hold adjustment, it must be turned (resurfaced) or replaced; a machine shop can do this for $15 to $40 per drum.
Tools and parts you'll need before starting
Gather your tools and parts before you begin. You'll need a jack and at least two jack stands rated for your vehicle's weight, a lug wrench, a socket set with wrenches in the sizes your vehicle uses (typically 10mm to 19mm), a brake spring removal tool (sometimes called a brake tool or spring tool — costs $8 to $15), a drum puller or slide hammer if the drum is stuck, and a container of brake cleaner. A wire brush and a small hammer are also useful for cleaning and tapping.
For parts, purchase a complete drum brake kit for your vehicle's make, model, and year. These kits include new brake shoes, return springs, hold-down springs, adjusters, and hardware — buying them as a kit ensures all pieces fit together. Kits typically cost $30 to $80 per wheel. You may also need new drums if the old ones are cracked or too worn to be resurfaced; have a machine shop measure your drums before you buy replacements. Brake fluid is not necessary for this job.
Removing the wheel and drum
Loosen the lug nuts on the wheel while the vehicle is still on the ground — this prevents the wheel from spinning when you explore force. Raise the vehicle with the jack and find it on jack stands; never work under a vehicle supported only by a jack. Remove the lug nuts completely and take off the wheel.
The drum is usually held by two small bolts or studs with nuts. Remove these fasteners and set them aside. If the drum slides off easily, you're ready to proceed. If it's stuck, spray penetrating oil around the edge where the drum meets the hub and let it soak for 10 to 15 minutes. Then use a drum puller (a three-jaw tool that bolts to the drum and pulls it off) or a slide hammer. Tap gently with a hammer around the drum's edge as a last resort — avoid striking hard enough to crack it.
Disassembling the old brake shoes and springs
Before you remove anything, take a clear photograph of the brake assembly from the side. This photo will show you exactly how the springs and shoes are arranged, which is invaluable when reassembling. The brake shoe assembly consists of two curved shoes held in place by springs and connected by an adjuster mechanism.
Use your brake spring tool to unhook the return springs — these are the larger springs that pull the shoes back when you release the brake pedal. Work carefully; the springs are under tension and can snap out suddenly. Next, remove the hold-down springs and pins that keep each shoe in place. These are smaller and usually held by a pin through the backing plate with a spring clip on the back. Slide the shoes out and remove the adjuster screw assembly (a threaded rod with a star wheel on one end). Clean the backing plate with brake cleaner and a wire brush to remove dust and debris.
Installing new brake shoes and hardware
Lay out all the new parts from your brake kit on a clean surface. Start by installing the adjuster screw assembly in the same position as the old one — this is the threaded rod that runs between the two shoes and allows the brakes to self-adjust as the shoes wear. Attach the new brake shoes to the backing plate using the new hold-down springs and pins, following your photograph and the kit's instruction sheet.
Install the return springs using your brake spring tool, hooking them between the shoes and the backing plate. The springs should pull the shoes together and hold them centered. Check that both shoes move freely and return to their resting position when you release them. Spin the adjuster star wheel a few times to may support it moves smoothly. The shoes should not touch the drum when you spin it by hand.
Reinstalling the drum and adjusting the brakes
Slide the drum back onto the hub and reinstall the bolts or nuts that hold it in place. Tighten them snugly but not with full force yet. Spin the drum by hand to make sure it rotates freely without rubbing. If it binds, the shoes are too close and you need to back off the adjuster or recheck your spring installation.
Once the drum spins freely, tighten the mounting bolts fully. Reinstall the wheel and tighten the lug nuts by hand, then lower the vehicle to the ground. Tighten the lug nuts in a star pattern (opposite sides alternately) to may support even pressure. Now adjust the brakes: spin the wheel and use a brake adjustment tool or a flathead screwdriver to turn the adjuster star wheel until the drum locks, then back it off about five clicks so the drum spins freely with light drag. Repeat this for the other brake shoe adjuster on the same wheel.
Testing and final steps
Before driving, pump the brake pedal several times while the vehicle is parked. The pedal should feel firm and not sink to the floor. If it does, you may have an air leak or a problem with your installation — stop and recheck your work. Start the engine and test the brakes at low speed in a safe area, such as an empty parking lot. The brakes should engage smoothly without noise or pulling to one side.
If you hear squealing or grinding, the shoes may not be seated properly or the drum may be damaged. If the brakes feel soft or the pedal sinks, recheck your spring installation and make sure all connections are tight. Some new brake shoes require a break-in period of 200 to 300 miles of gentle braking before they reach full stopping power, so avoid hard stops for the first few drives.
When to have a machine shop handle the drums
If your drums are scored, glazed, or warped, they should be resurfaced (turned) on a lathe at a machine shop. This removes a thin layer from the inside surface and restores a smooth finish. Most shops charge $15 to $40 per drum and can usually complete the work in one day. Bring both drums even if only one is damaged, so they're matched in size and finish.
If a drum is cracked or has been turned to its maximum allowable diameter (stamped on the outside), it must be replaced rather than resurfaced. Replacement drums cost $40 to $100 each depending on your vehicle. A machine shop can measure your old drums and tell you whether they can be turned or need replacement before you buy new shoes.
Frequently Asked Questions
Do I need to bleed the brakes after changing drum brakes?
No. Drum brake replacement does not require bleeding the brake system because you're not opening any hydraulic lines. Disc brake pad replacement sometimes requires bleeding, but drum shoes do not. Your brake fluid level may drop slightly as the new shoes take up more space in the wheel cylinders, so check your fluid level and top it off if needed.
What if the drum won't come off even with a puller?
Soak the drum with penetrating oil for several hours or overnight, then try again. If it's still stuck, tap around the edge gently with a hammer to break the rust seal. As a last resort, a machine shop can remove it with a hydraulic puller. Do not force it with excessive hammer blows, as you risk cracking the drum or damaging the hub.
Can I replace just one wheel's brakes or do I need to do both sides?
You can replace brakes on one wheel, but most mechanics recommend doing both wheels on the same axle (both rear wheels or both front wheels) at the same time. This ensures even braking and prevents the vehicle from pulling to one side. If only one wheel is worn, the other is likely close behind.
How do I know if my drums need resurfacing or replacement?
A machine shop can measure your drums and tell you whether they're within limits for resurfacing. If you see deep grooves, cracks, or a glazed (shiny, hardened) surface on the inside, the drums should be turned. If the inside diameter is already at or near the maximum stamped on the outside, replacement is necessary.
What's the difference between self-adjusting and manual-adjust drum brakes?
Self-adjusting brakes have a mechanism that automatically takes up slack as the shoes wear, so you don't need to adjust them manually. Manual-adjust brakes require you to turn the star wheel adjuster periodically. Most vehicles built after the 1970s have self-adjusting brakes, but the initial setup is the same — you adjust them once during installation, and the self-adjuster takes over from there.