how to turn brake drums

How to Turn Brake Drums A Step-by-Step Guide

Brake drums are a crucial component of a vehicle's braking system, especially in older models where drum brakes are still in use. Over time, brake drums can become warped, scored, or worn out due to regular wear and tear, leading to decreased braking efficiency and safety. Turning or machining the brake drums is a common practice to restore their functionality. This article provides a comprehensive guide on how to turn brake drums safely and effectively.

Understanding Brake Drums

Before diving into the turning process, it’s essential to understand what brake drums are and how they function. Brake drums are cylindrical components that house brake shoes and are part of the drum brake system. When the driver presses the brake pedal, hydraulic force pushes the brake shoes against the inner surface of the drum, creating friction that slows down or stops the vehicle.

If the inner surface of the drum becomes uneven or damaged, the brakes may pulse, squeak, or fail to work efficiently. Turning the brake drums helps restore a smooth surface for the brake shoes to contact, thus improving braking performance.

Tools and Materials Needed

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

- A brake drum lathe - Appropriate cutting tools - Safety goggles and gloves - Measuring tools (calipers and micrometers) - Brake cleaner - Shop towels - Torque wrench - Vehicle jack and jack stands

Step-by-Step Guide to Turning Brake Drums

Always prioritize safety when working on brake components. Wear safety goggles and gloves to protect yourself from debris and cleaning agents.

Step 2 Remove the Brake Drum

1. Lift the Vehicle Use a vehicle jack to lift the car and secure it on jack stands. 2. Remove the Wheel Take off the wheel to access the brake drum. 3. Detach the Brake Drum If the drum is held on by screws, remove them. Gently tap the drum with a hammer if it is stuck or rusted.

Step 3 Inspect the Brake Drum

Before turning the brake drum, inspect it for severe cracks or damage. Measure its thickness using calipers. Most brake drums have a minimum thickness specification; if the drum is below this limit, it should be replaced rather than turned.

Step 4 Setting Up the Brake Drum Lathe

1. Mount the Drum Secure the brake drum on the lathe’s spindle, making sure it is centered correctly to avoid uneven cuts. 2. Adjust the Cutting Tool Position the cutting tool to the correct depth, usually a few thousandths of an inch, to ensure that only a thin layer is removed.

Step 5 Turn the Brake Drum

1. Turn On the Lathe Start the lathe and slowly feed the cutting tool into the drum. Ensure a steady, even pressure is applied. 2. Monitor the Process Keep an eye on the rotation and listen for any unusual sounds. Adjust the feed rate as necessary. 3. Check for Evenness After machining, use measuring tools to check the inner surface for evenness and consistency.

Step 6 Clean and Reinstall the Drum

1. Clean the Drum Use brake cleaner and shop towels to remove any dust and debris from the machined surface. 2. Reattach the Drum Place the brake drum back onto the axle and secure it. Ensure to follow the manufacturer’s torque specifications when tightening. 3. Reinstall the Wheel Put the wheel back on, lower the vehicle off the jack stands, and tighten the lug nuts in a crisscross pattern.

Maintenance Tips

To prolong the lifespan of your brake drums, regularly inspect the braking system, keep the brake components clean, and replace worn-out parts promptly. Also, ensure that the brake shoes are compatible with the drum and properly adjusted to avoid excessive wear.

Conclusion

Turning brake drums is a practical skill that can enhance your vehicle's braking performance. While it requires precision and attention to detail, following the proper steps and safety precautions will ensure a successful outcome. If you are unfamiliar with this process, consider seeking help from a professional mechanic to ensure your vehicle remains safe and reliable. By maintaining your brake drums, you not only improve your vehicle’s performance but also contribute to your safety on the road.