How to

How To Measure Brake Drum Size – Simple Measuring Guide

How To Measure Brake Drum Size

Brake drums are what you see around the brake shoes. They are capable of expanding to push the shoes so that they come in contact with the drum. These brakes are wheel cylinder bores that essentially protect the shoes. They are made of metal and are much stronger than the shoes themselves. However, they are not invincible. Over time, they will also degrade. Only until a certain measurement will they do their job. Anything more or less than that will cause the whole system to suffer.

If you are unsure about your brake drum and would like to measure it to see if it is the right size, you have come to the right place. We shall walk you through the process in easy steps.

How To Measure Brake Drum Size

How To Measure Brake Drum SizeTo start off with, you will need a drum puller. Use it to remove the drum. You may also need a screwdriver and a drum brake spoon to adjust the shoes in order to make the removal easier. Once that is done, follow the steps below:

  • Find the maximum diameter in the cast. It is usually stamped on the rotor, on the outer side. Sometimes, due to rust, you may not be able to make out the measurements. In this case, you will need a specifications chart to get the value. Please note that every vehicle is different. So, you should be very careful about it and only rely on the stamp or the chart to get the right measurements.
  • Now, making sure that the interior diameter is facing upwards, lay the drum down on a flat surface.
  • Inspect the entire drum for cracks and grooves. These are usually around the anvils.
  • Choose any of the extendable arms of the micrometer and loosen the lock screw. Take the actual size into account and mark it down. If it is 10.5 inches, set the arms at 10 inches. Then, stamp the remainder in 4 places. 
  • Take the anvils and place them in any of the grooves. Now, use the micrometer by moving it back and forth to get the measurement. We advise you to take multiple measurements and record the highest number.
  • Add this number to the 10.5-inch diameter and compare it to the specifications. This will let you know if you can repair or machine the drum brake or if you should replace it completely.
  • You can also measure the thickness of the shoes using a depth gauge to ensure that they are the right size.

We hope this guide helped you understand how to measure a drum brake easily. If you still have doubts, you can always reach out to us. We are here to help.

Francis Ceron

About Francis Ceron

Did you know the major cause of car failures are due to spark plugs. At sparklplugs guru you wil find all the necessary reviews, guides and facts to improve the performance of your vehicle and have a smooth functioning.

Back to list

Leave a Reply

Your email address will not be published.