How to Replace Rear Drum Brake Shoes

Replacing rear drum brake shoes is a fundamental maintenance task that enhances vehicle safety and extends the life of your braking system. Drum brakes, common on rear axles, rely on curved shoes pressing against a rotating drum to create friction for stopping power. Over time, these shoes wear down, leading to reduced performance and potential hazards. This guide provides a thorough, original walkthrough to help you perform the replacement confidently at home.

Understanding Drum Brake Fundamentals

Drum brakes operate via a self-energizing mechanism where the shoes expand outward against the inner drum surface. Key components include primary and secondary shoes, hold-down springs, adjuster mechanisms, parking brake cables, and the wheel cylinder that supplies hydraulic pressure. Wear indicators like squealing or a spongy pedal signal it’s time for replacement. Regular inspection prevents issues such as uneven wear or contamination from grease and moisture.

• Primary Shoe: Contacts the drum first during forward braking.
• Secondary Shoe: Handles more load in reverse, often wearing faster.
• Star Adjuster: Automatically or manually tightens shoes as they wear.
• Return Springs: Pull shoes back from the drum after braking.

Essential Tools and Materials Checklist

Gather these items before starting to ensure a smooth process. Quality tools reduce frustration and prevent damage.

Always match parts to your vehicle’s make, model, and year. Consult the owner’s manual for torque specs.

Prioritizing Safety in Brake Work

Brakes are critical; errors can lead to accidents. Park on level ground, engage the parking brake, and chock wheels. Wear safety glasses and gloves. Disconnect the battery if working near electronics. Never work under a vehicle supported only by a jack—use rated stands. After installation, bed in the brakes gradually by performing controlled stops from low speeds.

Preparation: Pre-Removal Assessment

Begin with the vehicle cooled down. Loosen lug nuts slightly while on the ground. Jack up the rear, secure on stands, and remove the wheel. Photograph the assembly for reference. Inspect the drum exterior for cracks or excessive rust. Note parking brake cable condition and fluid levels in the master cylinder.

Detailed Drum Removal Procedure

The drum often sticks due to rust or adjuster tension. First, locate the access hole in the backing plate. Insert a flathead screwdriver to back off the star adjuster by rotating it counterclockwise until loose. Tap the drum gently with a rubber mallet around the edge to break the seal. Pull it straight off the hub. If seized, apply penetrating oil and wait 10-15 minutes.

1. Verify adjuster is fully retracted.
2. Inspect drum inner surface for scoring, glazing, or heat cracks.
3. Measure drum diameter; resurface if under 0.060 inches over spec, replace if more.

Disassembling the Brake Shoe Assembly

With the drum off, spray brake cleaner liberally. Relieve spring tension using a brake spoon. Remove hold-down pins by compressing springs with pliers and twisting 90 degrees. Disconnect return springs, noting their positions. Detach the parking brake strut and cable from the lever. Separate shoes from the adjuster assembly carefully to avoid bending components.

• Label springs: upper, lower, and adjuster types differ.
• Check wheel cylinder for leaks—dampness indicates seals need replacement.
• Inspect backing plate for grooves; sand smooth if minor.

Lay parts on a clean surface mirroring their original layout for reassembly accuracy.

Inspecting and Cleaning Components

Scrub the backing plate with a wire brush to remove rust and debris. Clean the star adjuster threads; lubricate lightly with brake grease if sticky. Test parking brake cable for free movement. Discard old springs—they lose tension over time. Examine the adjuster lever and clips for wear.

Installing New Brake Shoes

Start with the parking brake side. Hook the cable to the lever on the secondary shoe. Position shoes loosely near the hub. Connect the adjuster between shoes, ensuring the star wheel faces the access hole. Install the adjuster spring behind it. Slide the assembly onto the backing plate, securing with hold-down pins—turn to lock.

1. Attach lower return spring first.
2. Install self-adjuster lever and its spring.
3. Hook upper springs, stretching firmly with pliers.
4. Reconnect parking brake strut.

Ensure no twists in springs and shoes sit flat against the plate.

Fine-Tuning the Adjuster and Drum Seating

Through the access hole, turn the star adjuster clockwise with a brake spoon until shoes lightly drag on the drum. Insert the clean drum onto the hub. Adjust further until slight resistance when rotating by hand, then back off 10-12 notches for free spin. Match resistance on both sides. Secure the access plug.

Reassembly and Final Checks

Reinstall the wheel, hand-tighten lugs. Lower the vehicle and torque lugs in a star pattern to spec (typically 80-100 ft-lbs). Top off brake fluid if needed. Pump the pedal repeatedly until firm. Perform a short test drive: check for pulling, noises, or pedal fade. Readjust if the pedal sinks excessively.

Common Challenges and Solutions

Post-Installation Maintenance Best Practices

Bed in brakes with 10 moderate stops from 30 mph, avoiding hard braking. Recheck adjustments after 100 miles. Monitor fluid levels weekly initially. Replace drums if resurfacing isn’t viable. For ABS-equipped vehicles, scan for codes post-job.

FAQs

This procedure restores braking efficiency, but if unsure, consult a professional. Proper execution ensures safe, reliable stops.