How to Determine If Your Brake Drum Is Out of Round

nov . 28, 2024 16:07 Back to list

How to Determine If Your Brake Drum Is Out of Round

How to Measure Brake Drum Out of Round

Brake drums are a crucial component in the braking system of vehicles, particularly those with drum brakes. Over time, these drums can become 'out of round,' which means they no longer maintain their circular shape. This condition can lead to various braking issues, including vibrations, reduced braking effectiveness, and increased wear on brake components. Accurately measuring whether a brake drum is out of round is essential for vehicle safety and performance. Here’s how you can measure it, step by step.

Tools Required

To measure brake drum runout or being out of round, you will need the following tools

1. Dial Indicator This precision tool will allow you to measure the runout of the brake drum. 2. Base or Stand for Dial Indicator A stable mount is necessary to hold the dial indicator in place. 3. Ruler or Caliper For any additional measurements you may need. 4. Wrenches To remove the brake drum if needed.

Steps to Measure Brake Drum Out of Round

1. Safety Precautions

Always ensure the vehicle is parked on a flat surface and that the parking brake is engaged. Wear safety glasses and gloves to protect yourself during this process.

2. Remove the Wheel

If you need to access the brake drum, start by loosening the lug nuts slightly with a wrench
. Then, jack up the vehicle and remove the wheel to expose the brake components.

3. Inspect the Brake Drum

Before measuring, visually inspect the brake drum for signs of damage or excessive wear. Look for cracks, grooves, or any irregularities that could affect measurement.

how to measure brake drum out of round

How to Determine If Your Brake Drum Is Out of Round

4. Mount the Dial Indicator

Set up your dial indicator on a sturdy base, ensuring it is stable. Position the tip of the dial indicator so that it lightly touches the surface of the brake drum. The indicator should be perpendicular to the surface of the drum for the most accurate reading.

5. Rotate the Brake Drum

Slowly rotate the brake drum by hand while watching the dial indicator. The needle on the dial will move as the drum rotates. You should note the highest and lowest readings on the dial indicator.

6. Calculate the Runout

The difference between the highest point and the lowest point is the total runout. For example, if the highest reading is 0.020 inches and the lowest reading is 0.010 inches, the runout would be 0.010 inches.

Typically, a permissible runout for brake drums is around 0.005 to 0.015 inches, but you should confirm this with the vehicle’s specifications. If your measurements exceed this range, the drum may require machining or replacement.

7. Reinstall Components

After measuring, if the brake drum is in acceptable condition, carefully reinstall the wheel. If adjustments or replacements are necessary, consult a professional mechanic if you're unsure about the next steps.

Conclusion

Measuring brake drum out of round is a straightforward process that can prevent larger braking issues down the road. Regular checks and maintenance of brake components are essential for vehicle safety. If you find that your brake drum is excessively out of round, consider whether it can be machined or if a replacement is necessary. Proper care and monitoring of your braking system not only enhance performance but also ensure the safety of you and your passengers on the road.