How To Adjust Emergency Brake

The emergency brake, also known as the parking brake or handbrake, is a crucial safety feature often overlooked until needed. While modern vehicles rely heavily on sophisticated braking systems, the emergency brake provides a mechanical backup, ensuring the vehicle remains stationary when parked or in the event of a primary brake failure. Over time, the emergency brake cable can stretch, the pads can wear, or the self-adjusting mechanisms can fail, leading to a loss of effectiveness. Knowing how to adjust your emergency brake is essential for maintaining vehicle safety and preventing potential accidents. This article provides a comprehensive guide to adjusting various types of emergency brake systems.

Understanding Emergency Brake Systems

Before diving into the adjustment process, it’s vital to understand the different types of emergency brake systems commonly found in vehicles:

Drum Brakes: This is the traditional setup where the emergency brake actuates shoes inside a drum, typically located within the rear rotors.
Disc Brakes with Integrated Drum: These systems feature a small drum brake assembly integrated within the rear disc brake rotor specifically for the emergency brake. This design leverages the benefits of disc brakes for primary stopping power while retaining a robust mechanical parking brake.
Disc Brakes with Caliper Actuation: In some modern vehicles, the emergency brake directly actuates the rear disc brake calipers, either mechanically or electronically. These systems often use a separate cable or motor to apply pressure to the brake pads.

Regardless of the system type, the principle remains the same: applying mechanical force to create friction and prevent wheel rotation.

Tools and Safety Precautions

Before you begin, gather the necessary tools and prioritize safety:

Jack and Jack Stands: Essential for safely lifting the vehicle and securing it. Never work under a vehicle supported only by a jack.
Wheel Chocks: Place these behind the wheels that remain on the ground to prevent rolling.
Wrench Set: Metric or SAE, depending on your vehicle. Refer to your owner's manual for specific sizes.
Pliers: For manipulating cables and springs.
Screwdrivers (Phillips and Flathead): Various sizes for accessing adjustment mechanisms.
Penetrating Oil: To loosen corroded parts. PB Blaster or similar products are highly recommended.
Gloves and Safety Glasses: Protect your hands and eyes.
Torque Wrench: For tightening components to the manufacturer's specifications.

Safety First: Always work on a level surface, engage the parking brake (before starting the adjustment), and disconnect the negative battery cable to prevent accidental electrical activation, especially if your vehicle has an electronic parking brake.

Adjusting Emergency Brakes on Drum Brakes

Drum brake systems typically feature an adjuster mechanism located inside the brake drum. Here's a general procedure:

Loosen the Star Wheel Adjuster: This is often the most challenging part. Access the adjuster through a small slot in the backing plate. Use a brake spoon or a small screwdriver to turn the star wheel adjuster. You may need to use two screwdrivers – one to move the self-adjuster lever and another to turn the star wheel. Turn the star wheel to retract the brake shoes. Penetrating oil might be necessary to loosen a corroded adjuster.
Remove the Rear Wheels and Drums: Once the shoes are retracted enough, the drum should slide off. If it’s stuck, gently tap the drum with a rubber mallet. Inspect the brake shoes for wear and damage. Replace if necessary.
Inspect and Clean the Components: Check the condition of the springs, levers, and cables. Clean away any dust or debris with brake cleaner.
Adjust the Star Wheel: Turn the star wheel adjuster until the brake shoes just barely contact the drum when it’s reinstalled. You should feel a slight drag when rotating the drum by hand.
Reinstall the Drums and Wheels: Torque the lug nuts to the manufacturer's specifications.
Adjust the Cable Tension: Locate the cable adjuster, usually beneath the vehicle, near the center. Tighten the adjuster until the emergency brake engages firmly after a few clicks of the lever or pedal. Don’t overtighten, as this can cause the brakes to drag.

Adjusting Emergency Brakes on Disc Brakes with Integrated Drum

This system combines the simplicity of a drum brake for parking with the performance of disc brakes for regular stopping. The adjustment procedure is similar to that of a traditional drum brake:

Access the Adjustment Mechanism: The adjustment mechanism is typically located within the rotor. Some rotors may have a small access hole covered by a rubber plug.
Adjust the Star Wheel: Using a screwdriver or brake spoon, turn the star wheel adjuster until the parking brake shoes just make contact with the inside of the rotor when it's reinstalled. You should feel a slight drag when rotating the rotor.
Adjust Cable Tension (if needed): In some cases, you may also need to adjust the cable tension at a central adjuster point. Refer to your vehicle's service manual for specific instructions.

Adjusting Emergency Brakes on Disc Brakes with Caliper Actuation

These systems can be either mechanically or electronically actuated. Electronic parking brakes (EPB) typically require specialized diagnostic tools for adjustment and are best left to professionals. For mechanical systems:

Locate the Cable Adjuster: This is usually near the parking brake lever or pedal.
Adjust Cable Tension: Tighten or loosen the cable adjuster until the parking brake engages firmly after a few clicks of the lever or pedal. Ensure both rear wheels lock evenly when the parking brake is applied.
Inspect Caliper Levers: Check that the levers on the calipers move freely and return to their resting position when the parking brake is released. Lubricate if necessary.

Fine-Tuning and Testing

After adjusting the emergency brake, it’s crucial to fine-tune and test its performance:

Lever/Pedal Travel: The emergency brake should engage firmly after 3-7 clicks (or equivalent pedal travel).
Wheel Drag: With the emergency brake released, the wheels should rotate freely without any noticeable drag.
Holding Power: Test the emergency brake on a slight incline to ensure it holds the vehicle securely. Gradually increase the incline to verify its effectiveness.
Even Engagement: Ensure both rear wheels lock evenly when the emergency brake is applied. Uneven engagement can indicate a problem with one of the brake mechanisms.

If you notice any of the following issues, re-adjust the system or consult a qualified mechanic:

Excessive Lever/Pedal Travel: Indicates loose cables or worn brake components.
Wheel Drag: Suggests overtightened cables or a malfunctioning release mechanism.
Uneven Engagement: Points to a problem with one of the brake mechanisms, such as a seized cable or a faulty adjuster.
Weak Holding Power: Could be caused by worn brake shoes, contaminated surfaces, or stretched cables.

Maintenance and Common Problems

Regular maintenance can prevent emergency brake problems:

Cable Lubrication: Periodically lubricate the emergency brake cables to prevent corrosion and ensure smooth operation.
Brake Shoe/Pad Inspection: Regularly inspect the brake shoes or pads for wear and replace them as needed.
Adjuster Cleaning: Clean and lubricate the adjuster mechanisms to prevent them from seizing.

Common emergency brake problems include:

Stretched Cables: Result in excessive lever/pedal travel and reduced holding power.
Seized Cables: Prevent the brakes from fully releasing, leading to wheel drag.
Corroded Adjusters: Make it difficult or impossible to adjust the brake tension.
Worn Brake Shoes/Pads: Reduce the braking force and require replacement.

When to Seek Professional Help

While many emergency brake adjustments can be performed by DIYers, some situations warrant professional attention:

Electronic Parking Brakes (EPB): These systems often require specialized diagnostic tools and knowledge.
Complex Repairs: If you encounter significant corrosion, broken parts, or are uncomfortable working on your vehicle's brakes, it's best to consult a qualified mechanic.
Uncertainty: If you are unsure about any aspect of the adjustment process, seek professional help to avoid damaging your vehicle or compromising its safety.

By understanding the principles of emergency brake operation and following these adjustment guidelines, you can ensure your vehicle remains safe and reliable. Remember to prioritize safety and consult a professional when needed. Regular maintenance and prompt attention to any issues will help keep your emergency brake in optimal condition for years to come.