How to Adjust a Rear Disc Parking Brake

Identify which system you have (drum-in-hat shoes, integrated mechanical caliper, or electronic parking brake), adjust the foundation brake first (shoes or caliper self-adjust), then set cable slack so the brake holds with reasonable lever/pedal travel; for electronic systems, use service mode and finish with calibration. Below is a detailed, step-by-step guide to do it safely and correctly.

Know Your Rear Disc Parking Brake Type

Not all rear disc parking brakes adjust the same way. Determining your system ensures you use the correct procedure and avoid damage.

• Drum-in-hat (internal shoes inside the rotor “hat”): Most common on rear-disc cars. Adjustment is via a star-wheel expander like a traditional drum brake.
• Integrated mechanical caliper: The parking brake lever on the caliper applies the service pads. The piston is usually screw-type and self-adjusting; you reset/prime the mechanism, then set cable slack.
• Electronic parking brake (EPB): An electric motor actuates the parking brake (either on the caliper or on the cable). Many require a scan tool or service-mode procedure to retract/apply before adjustment and to calibrate afterward.

If you’re unsure, look behind the rear rotor: a small backing plate with a rubber plug suggests drum-in-hat shoes; a lever and cable directly on the caliper suggests integrated mechanical; electric connectors on the caliper or a dedicated EPB module points to an electronic system.

Tools and Preparation

Have the right tools and set up the vehicle safely before you begin any brake work.

• Wheel chocks, hydraulic jack, and jack stands (never rely on a jack alone).
• Lug wrench; common hand tools (sockets, wrenches, screwdrivers, pliers).
• Brake cleaner, anti-seize for adjuster threads, and a wire brush for rust.
• For integrated calipers: a piston rewind/cube tool if pads/rotor are removed.
• For EPB: a scan tool or the manufacturer’s service-mode sequence.
• Torque wrench for reassembly (follow your vehicle’s service specs).
• Safety gear: eye protection and gloves.

Work on level ground and keep the transmission in Park (auto) or in gear (manual) with the parking brake released during adjustments unless a step explicitly says to apply it.

Core Principles That Prevent Issues

These rules apply regardless of system type and help you avoid overheated brakes or poor holding power.

• Always adjust the foundation brake first (shoes or caliper self-adjust) to minimize travel.
• Adjust the cable last, only to remove slack—don’t “tighten” a weak brake with cable tension.
• Both sides must have equal drag; imbalance causes pull and uneven wear.
• If an adjuster or cable is seized, repair/replace it; do not force an adjustment.
• After any adjustment, verify lever/pedal travel and holding on a safe incline.

Following these principles ensures that the parking brake releases fully, holds when needed, and doesn’t overheat from constant light contact.

Procedures by System

Drum-in-Hat Parking Brake (internal shoes inside rear rotor)

This design uses miniature drum shoes for the parking brake with a star-wheel adjuster. You’ll set the shoe clearance first, then cable slack if needed.

1. Release the parking brake fully. Chock front wheels, lift the rear, and support with stands; remove rear wheels.
2. Locate the adjustment access. Many rotors have a rubber plug on the rotor hat or the backing plate. Remove the plug to see the star wheel.
3. Rotate the rotor to align the access with the star wheel. Using a brake spoon or flat screwdriver, turn the star to expand the shoes until the rotor locks, then back off gradually until the rotor spins freely with a faint, even rub.
4. Typical back-off is about 6–10 “clicks,” but rely on feel: a slight, uniform drag without heat after a short drive is ideal.
5. Repeat on the other side, matching the feel. Reinstall plugs.
6. Pump the parking brake lever/pedal several times to center the shoes. Recheck drag; fine-tune if necessary.
7. If lever/pedal travel is still excessive, adjust the cable at the equalizer (see Cable Adjustment section) to remove slack but avoid creating drag with the brake released.
8. Reinstall wheels, torque lugs to spec, lower vehicle, and perform a gentle test on flat ground, then on a mild incline.

Set the shoes so they’re close to the drum surface without dragging hard; then only minimal cable tension is needed to achieve proper holding with reasonable lever travel.

Integrated Mechanical Caliper (no EPB)

Here the parking brake lever on the caliper applies the service pads. The caliper typically self-adjusts as pads wear; your job is to reset/prime the mechanism and set cable slack.

1. Release the parking brake fully. Confirm the caliper’s parking brake lever returns firmly to its stop; free it up if sticking.
2. If pads/rotor are being replaced, screw the piston fully in using the proper rewind tool (do not clamp/press a screw-type piston). Install new parts.
3. Manually operate the caliper’s parking brake lever at the caliper several times to “prime” the internal adjuster until pad-to-rotor clearance is minimal and lever return is crisp.
4. At the cable equalizer (or at the lever end under the console), adjust the cable to remove slack so both caliper levers just reach their stops when released.
5. Check lever/pedal travel in the cabin. Aim for firm engagement within a reasonable range (often around 6–9 clicks on a hand lever, or about one-third to one-half stroke on a foot pedal).
6. Verify wheels spin freely when released. If there’s drag, back off cable slightly or address sticky caliper levers/cables.

The caliper’s internal adjuster sets pad clearance; the cable only removes slack. If holding is weak even with correct clearance, the caliper mechanism may be worn and need replacement.

Electronic Parking Brake (EPB)

EPB systems often require a service mode to safely retract/apply actuators and a calibration step after adjustment. Procedures vary; consult service documentation for your model.

1. Enter EPB service mode using a scan tool or the manufacturer’s pedal/ignition sequence so the actuators retract and won’t fight adjustment.
2. Adjust the foundation brake as applicable:
   

   • Drum-in-hat: Set shoe clearance via the star wheel as described above.
   • Caliper-integrated EPB: If pads/rotors are off, use the tool/scan command to retract, then reinstall and use the tool/command to apply/release to set pad clearance.

3. Adjust cable slack only if your EPB uses a cable with an accessible equalizer; some are motor-on-caliper with no cable to adjust.
4. Exit service mode and run the EPB calibration/initialization routine with the scan tool or vehicle procedure.
5. Confirm the brake applies and releases cleanly, with no warning lights, and that the wheels spin freely when released.

Never force EPB actuators without service mode; doing so can damage the motor or gears. If faults persist or you see EPB warnings, scan for codes and follow the diagnostic routine.

Cable Adjustment and Lever/Pedal Travel

Once the foundation brake is set, fine-tune the cable so engagement is prompt without causing residual drag.

1. Locate the equalizer nut (often under the center console, underbody mid-span, or at the foot pedal assembly).
2. With the brake fully released, tighten the nut until slack is removed and both sides begin to “just” pre-load, then back off slightly to ensure free rotation.
3. Check lever/pedal travel: many vehicles target firm hold within about 6–9 clicks on a hand lever or one-third to one-half travel on a foot pedal. Refer to your service manual for the exact spec.
4. Perform a rolling test at low speed: apply/release the parking brake to confirm even engagement and full release without pull or noise.

Proper cable adjustment provides consistent engagement feel and prevents one side from dragging due to asymmetrical tension.

Testing and Bedding

Verification ensures safety and identifies drag before it causes overheating or premature wear.

• Spin-test each rear wheel with the parking brake released; both should turn freely and similarly.
• Road-test on flat ground at low speed; apply the parking brake gently to check balance, then release and confirm no ongoing drag.
• Incline test: on a safe hill, the vehicle should hold without excessive lever/pedal force.
• After a short drive, carefully feel near the wheel (without touching hot components) or use an infrared thermometer; excessive heat on one side suggests drag and requires recheck.

Completing these checks immediately after adjustment helps catch issues before they become hazards or cause damage.

Troubleshooting and When Not to Adjust

If adjustment won’t yield proper operation, underlying faults may be the real cause.

• Seized or frayed cables: replace; do not overtighten to compensate.
• Glazed/contaminated shoes or pads, or a corroded rotor hat/drum: clean or replace parts.
• Frozen star wheel or broken hold-down hardware: service the shoe hardware kit.
• Sticking caliper parking lever or guide pins: clean/lubricate or replace caliper.
• EPB actuator faults or warnings: scan for codes; follow the factory diagnostic and calibration steps.
• Excessive lever travel even after correct shoe/pad setup: inspect for worn components or incorrect assembly.

Addressing root causes yields lasting results; overtightening cables to “fix” weak brakes typically leads to drag and premature wear.

Safety and Specifications

Brake work demands attention to detail and correct reassembly.

• Always support the vehicle securely with jack stands and chock wheels.
• Follow factory torque specs for caliper brackets, caliper slide bolts, and wheel lugs; values vary by model.
• Never rely on the transmission alone to hold the vehicle on a slope; the parking brake must function properly.
• If you lack access to service procedures for EPB, use a qualified technician—forcing components can cause costly damage.

When in doubt, consult the service manual for model-specific procedures, torque specs, and EPB service-mode instructions.

Summary

To adjust a rear disc parking brake, first identify the system. Set shoe or caliper pad clearance before touching the cable, use service mode and calibration for EPB, then fine-tune cable slack so the brake holds firmly with reasonable travel and releases without drag. Verify on a safe incline and address any seized or worn parts rather than masking issues with cable tension.

How do rear disc brakes self-adjust?

The single-piston floating-caliper disc brake is self-centering and self-adjusting. The caliper is able to slide from side to side so it will move to the center each time the brakes are applied.

How to adjust rear brake disc?

Now tighten the bolts to fix the calipers in position this fix is the same for mechanical. And hydraulic disc brake systems.

How does the parking brake work on disc brakes?

On a disc brake system, the parking brake mechanically actuates either a secondary drum brake assembly located inside the rear rotor hub, or it uses a corkscrew-like mechanism within the main caliper to mechanically push the pads against the disc. This bypasses the normal hydraulic system, using mechanical cables to engage shoes or a piston, applying pressure to the rotating disc or internal drum to lock the wheel.
 
This video shows how parking brakes work on disc brake systems: 1mVehicle EngineeringYouTube · Sep 8, 2020
How it works

1. Bypassing the Hydraulic System: The parking brake is a mechanical system, not a hydraulic one, so it can function even if the main hydraulic brakes fail. 
2. Cable-Driven Actuation: A hand lever or foot pedal is connected via cables to the rear wheels. 
3. Two Main Designs:
   • Drum-in-Hat System: A small drum brake is built into the center hub of the rear brake rotor. When the parking brake is engaged, the cables pull on levers that activate small brake shoes, which expand and press against the inside surface of the drum, stopping the car. 
   • Caliper-Actuated System: In this design, the mechanical linkage from the parking brake cable operates a mechanism within the brake caliper itself. 
     • This mechanism uses a corkscrew or screw-and-lever system. 
     • When the parking brake is pulled, the lever pushes a piston into the brake pads, forcing them against the brake rotor. 
4. Self-Locking Mechanism: The lever or pedal has a ratchet mechanism that locks in place to hold the brake applied until the release button is pressed. 

This video explains how a drum-in-hat parking brake works: 46sCodyYouTube · Jan 7, 2017
In summary
Regardless of the type, the mechanical linkage of the parking brake uses a different force than the primary hydraulic system. It applies pressure to the brake components (either inside a drum or via the caliper) to hold the rear wheels in place.

How to adjust the rear parking brake?

To adjust a rear parking brake, locate the rubber access plug on the rear rotor, remove it, and insert a screwdriver into the slot to turn the star wheel. Expand the brake shoes by rotating the star wheel until the rotor just locks, then turn the wheel backward to loosen it. Reinstall the rubber plug and wheel, and repeat on the other side. You may also need to adjust the parking brake cable for proper tension. 
Step-by-Step Adjustment

1. Secure the Vehicle: Chock the front wheels and raise the rear of the vehicle securely on jack stands. 
2. Remove the Wheel: Loosen and remove the lug nuts, then take off the rear wheel. 
3. Access the Adjuster: Locate the rubber plug on the disc brake rotor and remove it. 
4. Find the Star Wheel: Rotate the rotor until the star wheel adjustment screw is visible through the access port. 
5. Expand the Shoes: Insert a screwdriver into the star wheel’s teeth and rotate it (usually clockwise, or toward the bottom) to expand the brake shoes. 
6. Check for Drag: Continue rotating the star wheel until you can no longer turn the rotor by hand. 
7. Back Off the Adjustment: From the fully locked position, back the adjuster off a specific number of clicks (often eight). 
8. Reinstall: Replace the rubber plug and reinstall the wheel, tightening the lug nuts by hand. Lower the vehicle. 
9. Repeat on the Other Side: Perform the same adjustment procedure on the other rear wheel. 
10. Test the Brake: After lowering the vehicle and removing the wheel chocks, test the parking brake by ensuring it holds the car securely with the proper number of clicks on the lever. 

Cable Tension Adjustment 

• Locate the adjuster: In some vehicles, a separate adjustment is made on the parking brake cable, often found by removing the center console.
• Tighten the nut: Turn the adjuster nut to increase cable tension, making the parking brake engage with fewer lever clicks.
• Verify operation: The goal is enough tension to hold the vehicle securely but not so much that the brakes drag when released.