Brake drums are currently applied only on the rear axle and are not easy to replace. If you notice that the rear brakes are weaker or the parking brake is less efficient than before, you should have the drum braking system inspected. Replacing drums requires specialist tools. This is why it should be done by a specialized garage. Changing drums requires also changing the brake shoes and - in many car models - also the wheel bearings.
When should brake drums be changed?
Changing brake drums is a complicated procedure requiring specialist tools and knowledge about how brake drums are built and operate. They must be changed when the thickness of their working surface goes down below the value impressed on each drum. They may also need replacing if damaged by brake discs unchanged when required.
How are brake drums changed?
Changing a brake drum requires removing a wheel and disassembling the drum, which is frequently connected with removing the wheel bearing, and, consequently, replacing brake shoes. This, in turn, requires disassembling and reassembling the brake shoe adjuster lever.
The parking brake, also referred to as the hand brake, generally operates by means of drum brakes. This is why it must be disconnected from the shoes and then properly fitted back in place and adjusted. A wheel bearing removed together with a wheel is usually unfit for further use and requires changing.
Finally, one must not forget to check the level of the braking fluid in the brake fluid reservoir on the brake pump. It is also worth to check the boiling point of the brake fluid by means of a special tester. The whole procedure should be followed by a test drive and a brake test on a diagnostic path.
What else to keep in mind?
The useful life of brake drums depends largely on your driving style, but generally, one set of drums should run for approximately 100-150 thousand kilometres. This is why a good idea is to choose good quality drums to avoid having to go through the above procedure too often.