How To Replace Rear Disc Brakes?

Replacing rear disc brakes is a common maintenance task that can save you money and ensure your vehicle's safety. This guide provides a comprehensive, step-by-step walkthrough of the process, empowering you to confidently tackle this job in your garage. Understanding the procedure and taking the proper precautions is crucial for a successful and safe brake replacement.

This guide aims to provide clear, concise, and easily understandable instructions for replacing your rear disc brakes. By following these steps, you can ensure your vehicle's braking system is functioning optimally, contributing to your safety and the safety of others on the road.

Topic	Description	Importance/Benefit
Tools and Materials	List of essential tools and materials needed for the job.	Having the right tools ensures efficiency, safety, and prevents damage to components.
Safety Precautions	Crucial safety measures to prevent injury during the process.	Prioritizes personal safety and avoids potential accidents.
Preparation	Steps to prepare the vehicle and workspace before starting the replacement.	Creates a safe and organized environment for efficient work.
Removing the Wheel	Detailed instructions on safely removing the rear wheel.	Provides access to the rear brake assembly.
Inspecting the Brake System	Examining the condition of various brake components.	Identifies potential issues beyond just the pads and rotors.
Removing the Caliper	Step-by-step guide to safely removing the brake caliper.	Allows access to the brake pads and rotor.
Removing the Brake Pads	Instructions on removing the old brake pads from the caliper.	Prepares the caliper for new pads.
Compressing the Caliper Piston	Correct method for retracting the caliper piston.	Necessary to accommodate the new, thicker brake pads.
Cleaning and Lubricating	Cleaning and lubricating critical brake components.	Ensures smooth operation and prevents premature wear.
Removing the Rotor	Instructions on removing the old brake rotor.	Allows for rotor replacement or resurfacing.
Installing the New Rotor	Correct procedure for installing the new brake rotor.	Ensures proper fit and function of the braking system.
Installing the New Brake Pads	Instructions on installing the new brake pads into the caliper.	Restores the friction surface for braking.
Reinstalling the Caliper	Step-by-step guide to reattaching the brake caliper.	Secures the braking system.
Reinstalling the Wheel	Safe procedure for reinstalling the rear wheel.	Completes the brake replacement process.
Brake Bleeding (If Necessary)	Explanation of when and how to bleed the brakes.	Removes air from the brake lines for optimal braking performance.
Testing the Brakes	Steps to test the brakes and ensure proper function.	Verifies the success of the brake replacement and ensures safety.
Bedding In New Brakes	Procedure for properly seating new brake pads and rotors.	Maximizes braking performance and extends the life of the new components.
Troubleshooting Common Issues	Solutions to common problems encountered during brake replacement.	Provides guidance for resolving potential challenges.
Parking Brake Adjustment	How to adjust the parking brake after rear brake replacement.	Ensures proper functioning of the parking brake system.

Detailed Explanations

Tools and Materials:

This section outlines the essential tools and materials required for a successful rear disc brake replacement. Having the correct tools not only makes the job easier but also helps prevent damage to your vehicle. A comprehensive list includes:

New Brake Pads: Ensure you purchase the correct pads for your vehicle's make, model, and year.
New Brake Rotors (Optional): Inspect your rotors carefully. If they are warped, heavily scored, or below the minimum thickness specification, replace them.
Brake Caliper Piston Compression Tool: This tool is essential for retracting the caliper piston, especially on rear calipers with integrated parking brakes. A C-clamp may work, but a dedicated tool is highly recommended.
Socket Set: Various sizes will be needed for removing the wheel, caliper bolts, and other components.
Wrench Set: Similar to the socket set, a wrench set provides the necessary leverage for loosening and tightening bolts.
Torque Wrench: Crucial for tightening bolts to the manufacturer's specified torque. Over-tightening can damage components, while under-tightening can lead to brake failure.
Brake Cleaner: Used to clean brake components and remove contaminants.
Brake Lubricant (Specifically for Brakes): Used to lubricate caliper slide pins and other moving parts. Do NOT use regular grease.
Gloves: Protect your hands from dirt, grease, and brake dust.
Safety Glasses: Protect your eyes from debris.
Wheel Chocks: Secure the vehicle to prevent rolling.
Jack and Jack Stands: Essential for safely lifting and supporting the vehicle. Never work under a vehicle supported only by a jack.
Penetrating Oil: Helps to loosen rusted or seized bolts.
Wire Brush: For cleaning rust and debris from brake components.
Shop Rags: For cleaning up spills and wiping down components.
Brake Fluid (If Bleeding Brakes): Ensure you use the correct type of brake fluid for your vehicle (DOT 3, DOT 4, or DOT 5.1).
Brake Bleeding Kit (If Bleeding Brakes): Makes the bleeding process easier and more efficient. A simple one-person bleeder kit works well.
Rotor Retaining Screws (Optional): Sometimes these screws are corroded and need to be replaced.

Safety Precautions:

Safety should always be your top priority when working on your vehicle. Failing to follow these precautions can result in serious injury.

Always wear safety glasses and gloves. Brake dust can be harmful if inhaled or comes into contact with your skin.
Never work under a vehicle supported only by a jack. Always use jack stands placed on designated jacking points.
Use wheel chocks to prevent the vehicle from rolling. Place them behind the wheels on the opposite end of the vehicle from where you're working.
Work in a well-ventilated area. Brake cleaner and brake fluid can release harmful fumes.
Dispose of used brake fluid properly. Do not pour it down the drain. Take it to a recycling center or auto parts store.
Do not smoke or use open flames near brake fluid. Brake fluid is flammable.
If you are unsure about any step in the process, consult a qualified mechanic. Brake systems are critical safety components, and improper installation can have serious consequences.

Preparation:

Proper preparation is key to a smooth and efficient brake replacement.

Park the vehicle on a level surface.
Engage the parking brake.
Loosen the lug nuts on the rear wheel you'll be working on before lifting the vehicle. This makes it easier to remove the wheel once it's off the ground.
Gather all the necessary tools and materials. Having everything within reach will save you time and frustration.
Consult your vehicle's repair manual for specific instructions and torque specifications.
Protect the surrounding area with a drop cloth or cardboard. This will prevent brake fluid and other contaminants from staining your driveway or garage floor.

Removing the Wheel:

Removing the wheel provides access to the rear brake assembly.

Use the jack to lift the vehicle at the designated jacking point. Consult your owner's manual for the correct jacking points.
Place jack stands under the vehicle's frame for support. Ensure the jack stands are securely positioned.
Carefully lower the vehicle onto the jack stands.
Completely remove the lug nuts and carefully remove the wheel. Store the wheel safely out of the way.

Inspecting the Brake System:

A thorough inspection of the brake system can reveal potential problems beyond just worn pads and rotors.

Inspect the brake lines for cracks, leaks, or corrosion. Replace any damaged brake lines.
Check the brake caliper for leaks or damage. If the caliper is leaking, it will need to be rebuilt or replaced.
Examine the brake hoses for swelling, cracks, or kinks. Replace any damaged brake hoses.
Inspect the parking brake cable for damage or corrosion. A damaged parking brake cable can prevent the parking brake from functioning properly.
Check the condition of the wheel bearings. Worn wheel bearings can cause noise and vibration.

Removing the Caliper:

Removing the caliper allows access to the brake pads and rotor.

Locate the caliper mounting bolts on the back of the caliper.
Use a wrench or socket to remove the caliper mounting bolts. Penetrating oil may be needed if the bolts are rusted.
Carefully slide the caliper off the rotor. If the caliper is stuck, gently tap it with a rubber mallet.
Support the caliper with a wire or bungee cord. Do not let the caliper hang by the brake hose, as this can damage the hose.

Removing the Brake Pads:

Removing the old brake pads prepares the caliper for new pads.

Slide the old brake pads out of the caliper.
Note the position of any shims or clips. These will need to be reinstalled in the same position on the new brake pads.

Compressing the Caliper Piston:

Compressing the caliper piston is necessary to create enough space for the new, thicker brake pads.

Use a brake caliper piston compression tool to retract the piston. The specific tool required will depend on the type of caliper. Rear calipers often require a tool that both pushes and rotates the piston.
Slowly and carefully retract the piston. Avoid forcing the piston, as this can damage the caliper.
If you are using a C-clamp, be extremely careful not to damage the piston or the caliper. Place a piece of wood between the C-clamp and the piston to protect it.
Open the brake fluid reservoir cap before compressing the piston. This will prevent pressure from building up in the system.

Cleaning and Lubricating:

Cleaning and lubricating critical brake components ensures smooth operation and prevents premature wear.

Clean the caliper bracket with a wire brush. Remove any rust or debris.
Lubricate the caliper slide pins with brake lubricant. This will ensure that the caliper slides smoothly.
Apply a thin layer of brake lubricant to the back of the brake pads. This will help to prevent brake squeal.
Clean the rotor surface with brake cleaner. Remove any oil or grease.

Removing the Rotor:

Removing the old rotor allows for rotor replacement or resurfacing.

Remove the rotor retaining screw (if present). Penetrating oil may be needed if the screw is rusted. Use an impact driver if necessary.
If the rotor is stuck, gently tap it with a rubber mallet. Avoid hitting the rotor too hard, as this can damage the wheel bearings.
Apply penetrating oil to the center hub of the rotor.
Use a rotor puller if necessary.
Clean the hub surface with a wire brush.

Installing the New Rotor:

Correctly installing the new brake rotor ensures proper fit and function of the braking system.

Clean the new rotor with brake cleaner. Remove any protective coatings.
Position the new rotor on the hub.
Install the rotor retaining screw (if present). Tighten the screw to the manufacturer's specified torque.
Ensure the rotor is seated properly against the hub.

Installing the New Brake Pads:

Installing the new brake pads restores the friction surface for braking.

Install any shims or clips on the new brake pads. Ensure they are in the same position as they were on the old brake pads.
Slide the new brake pads into the caliper bracket.

Reinstalling the Caliper:

Reattaching the brake caliper secures the braking system.

Carefully slide the caliper over the brake pads and rotor.
Install the caliper mounting bolts.
Tighten the caliper mounting bolts to the manufacturer's specified torque.

Reinstalling the Wheel:

Reinstalling the wheel completes the brake replacement process.

Carefully position the wheel on the hub.
Install the lug nuts hand-tight.
Lower the vehicle until the wheel is just touching the ground.
Tighten the lug nuts in a star pattern to the manufacturer's specified torque.
Completely lower the vehicle.
Double-check the lug nuts to ensure they are properly tightened.

Brake Bleeding (If Necessary):

Bleeding the brakes removes air from the brake lines for optimal braking performance. This is typically necessary if the brake lines were opened or if the brake pedal feels spongy.

Locate the brake bleeder screw on the caliper.
Attach a clear hose to the bleeder screw and submerge the other end of the hose in a container of brake fluid.
Have a helper slowly pump the brake pedal several times and hold it down.
Open the bleeder screw while the pedal is held down.
Close the bleeder screw before the pedal reaches the floor.
Repeat this process until no more air bubbles come out of the hose.
Tighten the bleeder screw to the manufacturer's specified torque.
Repeat this process for all four wheels, starting with the wheel furthest from the master cylinder.
Check the brake fluid level in the master cylinder and top it off as needed.

Testing the Brakes:

Testing the brakes verifies the success of the brake replacement and ensures safety.

Pump the brake pedal several times to ensure it feels firm.
Start the engine and test the brakes at low speeds in a safe area.
Listen for any unusual noises.
Ensure the vehicle stops smoothly and evenly.
Check the brake fluid level in the master cylinder again.

Bedding In New Brakes:

Properly bedding in new brake pads and rotors maximizes braking performance and extends the life of the new components.

Perform several moderate stops from 30 mph to 10 mph.
Allow the brakes to cool down completely.
Perform several more aggressive stops from 45 mph to 15 mph.
Avoid hard braking for the first few hundred miles.

Troubleshooting Common Issues:

Solutions to common problems encountered during brake replacement.

Stuck Caliper Mounting Bolts: Use penetrating oil and a breaker bar to loosen the bolts. If the bolts are severely rusted, you may need to use a torch to heat them up.
Stuck Rotor: Use penetrating oil and a rubber mallet to loosen the rotor. A rotor puller may also be necessary.
Brake Squeal: Ensure that the brake pads are properly lubricated and that the rotors are clean. If the squeal persists, the brake pads may be of poor quality.
Spongy Brake Pedal: Bleed the brakes to remove any air from the brake lines.
Parking Brake Not Working: Adjust the parking brake cable according to the vehicle manufacturer's instructions.

Parking Brake Adjustment:

Adjusting the parking brake after rear brake replacement ensures proper functioning of the parking brake system. The adjustment procedure varies depending on the vehicle. Consult your vehicle's repair manual for specific instructions. Generally, it involves tightening or loosening a cable adjuster until the parking brake engages properly.

Frequently Asked Questions

How often should I replace my rear disc brakes? It depends on your driving habits, but typically every 30,000 to 70,000 miles. Regular inspections are key.

What are the signs that my rear disc brakes need to be replaced? Squealing or grinding noises, a pulsating brake pedal, or a longer stopping distance are common indicators.

Can I replace just the brake pads and not the rotors? Yes, if the rotors are in good condition (not warped, scored, or below minimum thickness).

What type of brake fluid should I use? Consult your vehicle's owner's manual for the correct type of brake fluid (DOT 3, DOT 4, or DOT 5.1).

How do I know the correct torque specifications for the bolts? Consult your vehicle's repair manual. Using the correct torque is crucial for safety.

Is it necessary to bleed the brakes after replacing the rear brakes? If you opened the brake lines, yes. It's also recommended if the brake pedal feels spongy after the replacement.

What is "bedding in" new brakes? It's a process of gradually heating and cooling the new pads and rotors to transfer brake pad material onto the rotor surface, optimizing performance.

Can I use regular grease on brake components? No! Only use brake lubricant specifically designed for brake components. Regular grease can damage rubber parts and reduce braking performance.

Conclusion

Replacing rear disc brakes is a manageable task for the average DIYer with the right tools, knowledge, and a commitment to safety. Remember to follow these instructions carefully, consult your vehicle's repair manual, and prioritize safety at all times to ensure a successful and safe brake replacement.