What Parts to Replace on Drum Brakes

Typical drum brake service replaces the brake shoes, the complete hardware kit (return springs, hold-downs, shoe-to-anchor spring), the self-adjuster assembly, and often the wheel cylinders; drums are replaced or machined only if within spec, and all work is done on both sides of the axle. In practice, a thorough service focuses on renewing the wear items and any hydraulic parts prone to leakage, ensuring consistent braking performance and longevity while meeting the drum’s stamped specifications.

Core components commonly replaced as a set

These are the parts most technicians change during a standard drum brake job because they wear out, lose tension, or corrode, and replacing them together helps prevent repeat visits and uneven braking.

• Brake shoes (primary/secondary): The friction linings that press against the drum; always replace in axle pairs.
• Hardware kit: New return springs, hold-down pins/springs/cups, and shoe-to-anchor spring to restore correct spring tension and shoe retention.
• Self-adjuster assembly: Star wheel/screw, lever (pawl), cable, guide, and related springs; adjusters wear, seize, or lose accuracy—replace both left and right (note that many vehicles use opposite-thread adjusters side-to-side).
• Wheel cylinders: Frequently seep or stick with age; many shops replace them proactively during shoe service, especially if boots are damp, pistons are sticky, or mileage is high.
• Brake drums (as needed): Replace if worn beyond “MAX DIA,” heat-checked, cracked, deeply scored, or cannot be trued within spec; otherwise light resurfacing is acceptable if it stays under the maximum diameter.

Treat these as the baseline package: fresh friction, springs, adjusters, and healthy wheel cylinders restore the system’s mechanical and hydraulic integrity, while drum replacement depends on measured condition.

Parts to inspect and replace if out of spec or damaged

Beyond the core set, several related components can compromise braking if worn or contaminated; inspect them carefully and replace when they show wear, leakage, or corrosion.

• Backing plate shoe contact pads: Check for grooves and lubricate lightly with high-temp brake grease; severe wear may require repair or replacement.
• Parking brake lever/strut and associated clips: Replace if seized, bent, or excessively worn; these affect shoe retraction and parking brake function.
• Anchor pin/bushings and guide plates: Renew if corroded or worn to maintain correct shoe geometry.
• Axle seals (rear) and hub grease seals (if drum integrates with hub/bearings): Replace at the first sign of leakage; oil or grease contamination ruins shoes.
• Wheel bearings (if serviceable within the drum/hub): Clean, inspect, repack or replace as needed; always install new seals.
• Flexible brake hose to the axle and wheel cylinder bleeder screws: Replace hoses that are cracked, swollen, or internally collapsed; replace stuck or corroded bleeders.
• ABS tone ring/sensor (if integrated near the drum): Inspect for damage or heavy rust; clean or replace if needed to avoid ABS faults.
• Fasteners and clips: Any distorted or corroded hardware that can’t be reused safely should be replaced.

Addressing these adjacent items prevents premature shoe contamination, ensures reliable adjustment and retraction, and keeps hydraulic and ABS systems functioning as intended.

When should the drums themselves be replaced?

Every brake drum is stamped with a “MAX DIA” (maximum inside diameter). Measure the drum with an internal drum gauge: if cleaning or machining would exceed that value, the drum must be replaced. Replace drums that are cracked, heat-checked, heavily scored, bell-mouthed, out-of-round beyond service limits, or cause pedal pulsation. Many passenger-vehicle drums allow roughly 0.040 in (1.0 mm) over nominal, but rely on the exact stamping and the service manual. If machining is needed, keep total indicated runout typically under about 0.006 in (0.15 mm) and ensure a proper surface finish.

One-axle rule: replace in pairs

Drum brake components should always be replaced and adjusted on both sides of the axle. Mixing old and new parts can cause pull, noise, and uneven braking or parking brake performance.

Tools and consumables you’ll need

Having the correct tools and supplies helps you remove strong springs safely, measure wear accurately, and reassemble components to spec.

• Brake spring pliers and a hold-down spring tool
• Brake spoon or flat screwdriver for star-wheel adjustment
• Drum gauge/micrometer (or internal caliper) to measure drum diameter
• Line wrenches for hydraulic fittings; new brake fluid (DOT 3/4 as specified)
• Bleeder bottle or vacuum/pressure bleeder
• High-temp brake grease for backing plate pads and adjuster threads
• Brake cleaner and a catch pan; avoid blowing dust with compressed air
• Torque wrench and correct lug nut torque specs
• Jack stands and wheel chocks for safe support

Using the right tools reduces the risk of damage, speeds up the job, and ensures precise measurements and safe reassembly.

Post-repair steps

After installing new parts, finishing adjustments and checks are essential to restore full braking performance and safety.

1. Set shoe-to-drum clearance: Adjust the star wheel until the drum slides on with slight, even drag.
2. Operate the parking brake repeatedly: On self-adjusting systems, this helps center and auto-adjust the shoes.
3. Bleed the wheel cylinders and consider a full brake fluid flush if fluid is dark or service interval is due.
4. Bed-in the shoes: Make a series of moderate stops from 30–40 mph to transfer material evenly, avoiding hard panic stops initially.
5. Recheck for leaks, noises, and heat after a short drive; re-torque lug nuts after 50–100 miles and verify parking brake hold.

These steps help ensure consistent pedal feel, quiet operation, and even shoe wear from the first miles after service.

Costs and parts naming tips

Expect approximate retail pricing per axle: shoes $25–70, hardware kit $10–25, self-adjuster kit $10–25 per side, wheel cylinders $10–30 each, drums $40–120 each (hub-integrated drums and heavy-duty applications can be higher), bearings/seals $20–60, and brake fluid $8–20. When ordering, ask for a “drum brake hardware kit” and a “self-adjuster repair kit,” and verify left/right adjuster threads; bring your VIN to match parts accurately.

Summary

For most drum brake services, replace the brake shoes, full hardware kit, self-adjuster assemblies, and often the wheel cylinders; resurface or replace drums based on measured condition, and service both sides of the axle. Inspect seals, bearings, hoses, and backing plate contact points, addressing any wear or leaks. Correct adjustments, fresh fluid, and a proper bed-in complete a reliable, quiet, and safe repair.

What drum brake part wears out?

The brake shoes I’ve marked with the red arrows and these are a frictional material like a brake pad, they’re designed to wear out but they wear out at a slow rate so that’s, that’s the main component that wears out as they press against the brake drums so like a brake rotor which wears out over time, the drums also …

What needs to be replaced on drum brakes?

When replacing drum brakes, you should always replace the brake shoes and the entire spring and hardware kit, which includes all return springs, hold-down springs, and clips. Additionally, it is highly recommended to replace the wheel cylinders and inspect and service the self-adjuster mechanism. If the drums themselves are warped, grooved, or pitted, they should also be replaced.
 
Parts to Replace

• Brake Shoes: Opens in new tabThese are the most common parts to replace as they are friction components that wear down over time. 
• Springs and Hardware Kit: Opens in new tabThis kit contains all the small springs, clips, and retainers that hold the brake system together. These can lose strength or break over time. 
• Wheel Cylinders: Opens in new tabInspect for leaks or damage, and replace them while you have the drum assembly apart. 
• Brake Drums (if necessary): Opens in new tabReplace the drums if they are warped, grooved, or pitted. 

Parts to Service

• Self-Adjuster Mechanism: Clean and lubricate the adjuster screw and the components of the self-adjuster assembly, even if they don’t seem to be the cause of the problem. 
• Backing Plate: Clean the contact points on the backing plate with a wire brush and apply brake grease or anti-seize. 

Why You Should Replace Everything

• Ensures Reliable Braking: Replacing all the components ensures the entire system functions correctly and safely. 
• Prevent Future Issues: Springs can lose their strength, and other hardware can break, leading to future problems. 
• Cost-Effective: Since the drum is already off, it’s efficient and recommended to replace the wheel cylinders and all hardware at the same time, as these parts are inexpensive. 

Is it hard to change drum breaks?

Changing drum brakes is more difficult than replacing disc brakes due to their many interconnected parts, such as springs, cables, and adjusters, but it is a manageable task with proper tools and caution. While requiring a careful and systematic approach, the process becomes easier with practice, and specialized brake tools can greatly simplify the job. 
Difficulty Factors

• Numerous parts: Unlike disc brakes with relatively few components, drum brakes have a complex assembly of springs, retainers, cables, and self-adjuster mechanisms. 
• Stuck drums: Rusted or corroded brake drums can be difficult to remove, sometimes requiring a mallet or other tools to free them. 
• Spring tension: The tension in the brake springs can be a safety hazard, making spring removal and installation a delicate process that requires caution. 

Tools Needed 

• Basic tools: You will need a hammer (or rubber mallet), pliers, screwdrivers, and potentially a wire brush for cleaning.
• Specialized tools: A drum brake tool kit, which includes specialized pliers and spring tools, can make the process significantly faster and easier.
• Safety equipment: Eye protection is essential due to the high-tension springs, and gloves are recommended to avoid brake dust and contamination.

Tips for a Smooth Process

1. Safety First: Always lift and support the car on jack stands on level ground. 
2. Document the Process: Take photos of the assembly before you start disassembling it to remember the proper placement of parts, especially springs and cables. 
3. Use a Mallet: A rubber mallet can be used to gently tap the drum and loosen it from the hub. 
4. Disconnect One Side at a Time: To avoid confusion, only disassemble one side of the drum brakes at a time. 
5. Replace All Hardware: It is highly recommended to replace all the springs, guides, and the self-adjuster along with the brake shoes. 
6. Adjust for the Drum: After installing new parts, adjust the self-adjuster so the shoes are snug against the drum to prevent the wheel cylinder from popping out. 

What are the 5 parts of a drum brake system?

Drum Brake Components

• Backing Plate. The backing plate is one of the drum brake components in the form of a metal-based band which is relatively thin and is placed on the back of the drum brake system.
• Wheel Cylinders.
• Brake Shoes and Pads.
• Return Spring.
• Brake Shoe Holder.
• Brake Shoe Adjuster.
• Parking Brake Lever.
• Drum Brake.