We’ve covered disc brakes, so now it’s time to tackle drum brakes.
The principle of semi-circular shoes acting against the internals of a machined drum that rotates as part of the hub assembly provided adequate stopping power for many years.
In addition, the components are protected from dirt and debris – an important consideration on early roads.
As front disc brakes became prevalent, drums continued to provide rear-axle braking largely because they allow a simple and effective handbrake system.
To get short and confidence-inspiring pedal travel, the clearance between the friction surface and the drum has to be minimised.
Shoe position is usually altered via an adjuster nut on the outside of the backplate, connected to a snail cam or wedge-shaped spreader.
Other systems use a rotating collar – accessed through a hole in the front face of the drum – to extend a threaded rod.
Some later designs have automatic adjusters, which can need some assistance as they age – Mk1 VW Golfs are notorious for this failing. Check your handbook or workshop manual to see exactly which system your car has fitted.
Classic brake pads may contain asbestos – wear a face mask, and use brake cleaner to damp down dust.
STEP 1: REMOVE DRUM
With one axle supported and the other chocked, take off the wheel and slacken the adjuster screws.
