how to bleed back drum brakes

How to Bleed Back Drum Brakes A Comprehensive Guide

Drum brakes are a crucial component of many vehicles, providing essential stopping power through friction. Over time, air can enter the brake fluid system, leading to a spongy pedal feel and reduced braking efficiency. Bleeding your drum brakes helps remove this air, ensuring optimal performance. This guide will walk you through the steps necessary to effectively bleed your drum brakes.

Tools and Materials You’ll Need

Before you begin the process, ensure you have the following tools and materials

1. Wrench Typically a 10mm wrench is required for the bleeder screws. 2. Clear Tubing To attach to the bleeder valve for collecting old brake fluid. 3. Brake Fluid Ensure you have the correct type as specified in your vehicle’s manual (usually DOT 3 or DOT 4). 4. Brake Bleeder Kit (optional) This can simplify the process. 5. Jack and Jack Stands To lift the vehicle safely. 6. Brake Cleaner To clean up any spills. 7. Rags or Towels For managing spills and maintaining a clean workspace.

Preparation Steps

1. Safety First Park your vehicle on a flat surface, engage the parking brake, and wear safety glasses to protect your eyes from brake fluid.

2. Lift the Vehicle Use a jack to lift the vehicle and secure it with jack stands. Ensure that it is stable before you start working.

3. Access the Drums Remove the wheels to gain access to the drum brakes. Depending on your vehicle, you may need to remove wheel covers or lug nut covers.

4. Locate the Bleeder Valve On your drum brakes, you’ll find a bleeder screw, usually located near the top of the brake assembly.

Bleeding the Brakes

1. Attach the Hose Slide one end of the clear tubing onto the bleeder screw, positioning the other end in a container to catch old brake fluid.

2. Check Brake Fluid Level Before bleeding, ensure the brake fluid reservoir is filled to the recommended level. If it’s low, top it off to prevent introducing more air into the system.

3. Turning the Bleeder Screw Follow these steps to bleed each brake

a. Open the Bleeder Use the wrench to slightly loosen the bleeder screw. Be cautious not to open it too much, as this can create a mess.

b. Pump the Brakes Have an assistant (or do it yourself if you're alone) pump the brake pedal several times firmly and then hold it down.

c. Release the Fluid While the brake pedal is held down, open the bleeder screw to let the brake fluid and air escape into the container.

d. Close the Screw Once a steady stream of fluid comes out (without air bubbles), close the bleeder screw while the pedal is still depressed.

e. Release the Pedal Allow your assistant to slowly release the brake pedal.

4. Repeat the Process Repeat the pump-and-bleed process several times until no air bubbles appear in the fluid. It’s often recommended to start with the wheel furthest from the master cylinder and work your way to the closest, typically in this order right rear, left rear, right front, and left front.

5. Check Fluid Levels After bleeding each brake, check the brake fluid reservoir frequently, topping it off as necessary to maintain the appropriate level.

6. Finishing Up Once all four brakes are bled, double-check the tightness of all bleeder screws to ensure there are no leaks.

Final Steps

1. Test the Brake Pedal Before driving, pump the brake pedal a few times to ensure it feels firm. A spongy pedal may indicate that more bleeding is necessary.

2. Replace the Wheels Once everything is in order, put the wheels back on and securely tighten the lug nuts.

3. Dispose of Old Fluid Properly Brake fluid is toxic, so be sure to dispose of it in a safe and environmentally friendly manner.

Conclusion

Bleeding your drum brakes is an essential maintenance task that can significantly impact your vehicle's safety and performance. By following these steps, you can ensure your brakes function properly and safely. If you’re uncomfortable performing this task or if problems persist, it’s always best to consult a professional mechanic. Regular checks and maintenance of your brake system are crucial to your safety on the road.