how much to turn brake drums

Dec . 18, 2024 08:52 Back to list

how much to turn brake drums

How Much to Turn Brake Drums A Complete Guide

Brake drums are a crucial component of a vehicle's braking system, especially in cars that utilize drum brakes. Over time, these drums can wear down, warp, or develop grooves that can compromise their effectiveness. One of the essential maintenance tasks is determining how much to turn brake drums to ensure optimal performance. In this article, we’ll cover what turning brake drums means, when it's necessary, and how to measure and perform the task effectively.

Understanding Brake Drums

Before diving into how much to turn brake drums, it's important to understand their function and design. Brake drums are metal cylinders that house brake shoes. When the brake pedal is pressed, the shoes are pushed against the inner surface of the drum, creating friction that slows down or stops the vehicle. Over time, this friction causes wear, leading to uneven surfaces, which can result in reduced braking efficiency, noise, and vibration.

When to Turn Brake Drums

Turning the brake drums, also known as resurfacing, is typically necessary when

1. Visible Wear If you notice significant grooves or scoring on the surface of the brake drum, it's a sign that they may need to be turned. 2. Vibration or Noise If there’s noticeable vibration or noise when braking, it could indicate that the drum is warped and needs adjustment. 3. Thickness Check Brake drums have a minimum thickness specification. If the drums are worn down too thin, they should be replaced rather than turned.

How Much to Turn Brake Drums

The amount to turn brake drums depends on the specific thickness and condition of your drums. Generally, a brake drum can be resurfaced up to a specified limit determined by the manufacturer. This limit is indicated on the drums themselves or in the vehicle’s service manual. Here are some steps to ensure you're turning drums correctly

how much to turn brake drums

1. Measure the Diameter Use a micrometer to measure the inside diameter of the drum. This will give you a baseline to compare against the maximum allowable diameter. 2. Check for Warping Place the drum on a lathe for inspection. A lathe can help identify any warping or unevenness. Ideally, the drum should have minimal deviation.

3. Determine Material Removal Manufacturers typically allow for a few thousandths of an inch (often around 0.060 inches) of material to be removed, but this can vary. Consult the specifications for your vehicle type.

4. Lathe Resurfacing If the drum is within tolerances and can be resurfaced, position it on the lathe and ensure it's securely fastened. The cutting tool should remove material evenly around the drum's surface until a smooth finish is achieved.

5. Final Measurement After turning, remeasure the inner diameter to ensure it hasn’t exceeded the maximum specifications provided by the manufacturer.

Choosing Between Turning and Replacement

Sometimes it may be more beneficial to replace the drums rather than turn them. If the drums are too worn down or if they’ve been turned multiple times in the past, new drums could provide better performance and safety. Additionally, replacement is often more cost-effective in the long term, as old drums may not hold up well under continued stress.

Conclusion

Turning brake drums can be a vital part of maintaining your vehicle's braking system. This task requires accuracy and attention to detail, as improper handling can lead to reduced braking efficiency or even brake failure. Ultimately, how much to turn brake drums will be determined by their current condition and manufacturer specifications. Regular inspections and maintenance will help ensure your vehicle remains safe and reliable on the road. Always consult a professional mechanic if you're unsure about the condition of your brake drums or the turning process. Making informed choices about brake maintenance is key to vehicle safety.