how adjust drum brakes

How to Adjust Drum Brakes A Comprehensive Guide

Drum brakes are a common type of braking system found in many vehicles, especially older models. While newer cars predominantly use disc brakes, drum brakes are still widely used for rear brakes due to their ability to provide strong stopping power. Adjusting drum brakes is an essential skill for vehicle maintenance, helping to ensure optimal performance and safety. In this article, we will explore a step-by-step guide on how to adjust drum brakes effectively.

Understanding Drum Brakes

Before delving into the adjustment process, it’s important to understand how drum brakes work. The system consists of a drum attached to the wheel, brake shoes that press against the inside of the drum to create friction, and a mechanism to engage and disengage the brake shoes. As the brake pedal is pressed, hydraulic fluid moves through the brake lines, forcing the brake shoes outward against the drum.

If the brake shoes are not properly adjusted, there can be excessive pedal travel, reduced braking capability, uneven shoe wear, or even brake drag, leading to increased wear on the components. Therefore, regular adjustment is crucial.

Tools and Materials Needed

Before starting the adjustment process, gather the following tools and materials

1. Jack and jack stands 2. Lug wrench 3. Brake shoe adjuster tool (or flathead screwdriver) 4. Wrench or socket set 5. Brake cleaner 6. Rags 7. Safety glasses and gloves

1. Safety First Begin by ensuring your safety. Park the vehicle on a flat surface, engage the parking brake, and wear safety glasses and gloves.

2. Lift the Vehicle Use a jack to lift the vehicle and secure it with jack stands. Remove the rear wheels using a lug wrench.

3. Remove the Brake Drum Inspect the drum for any visible damage. To remove the brake drum, you may need to take off the retaining screws. Once released, gently pull the drum off. If it’s stuck due to rust or debris, lightly tap it with a rubber mallet.

4. Inspect Components Take a moment to inspect the brake shoes, springs, and other components for wear or damage. Replace any worn parts as necessary.

5. Adjust the Brake Shoes - Locate the adjuster screw or wheel, usually found at the bottom of the brake assembly. This can be a star wheel or a threaded adjuster. - Use the brake shoe adjuster tool or flathead screwdriver to turn the adjuster. To expand the shoes, turn the adjuster wheel clockwise until you feel resistance. This may require several turns. - Once the shoes are snug against the drum, back off slightly to ensure they do not drag. A common practice is to adjust until the drum can just be installed with slight resistance.

6. Check Free Play Ensure there is a slight free play in the brake pedal. Typically, the pedal should have about 1-2 inches of travel before it engages the brakes. Adjust the rod connecting the pedal to the master cylinder if needed.

7. Reinstall the Brake Drum Once adjusted, slide the brake drum back onto the hub. Make sure it spins freely and does not rub against the shoes.

8. Reinstall the Wheel Put the wheel back on, hand-tighten the lug nuts, and lower the vehicle back to the ground. Once stable, torque the lug nuts to the manufacturer’s specifications.

9. Test the Brakes Before driving, pump the brake pedal a few times to seat the shoes against the drum. Test drive the vehicle at low speeds to ensure that the brakes work effectively and there is no dragging.

10. Final Checks After your test drive, double-check the brake component adjustments and inspect for any unusual noises or behaviors.

Conclusion

Adjusting drum brakes is a vital maintenance task that can enhance your vehicle's braking performance and safety. By following the outlined steps, you can ensure that your drum brakes are correctly adjusted, prolonging their lifespan and optimizing their functionality. Regular inspection and adjustment, especially after a significant amount of driving, can prevent more serious issues down the line. If you are ever unsure or uncomfortable performing brake adjustments, it’s always best to consult a professional mechanic. Remember, safety should always come first.