Drum Brake Mechanism

It is the brake lining which makes contact with brake drum during the stopping of the vehicle.

Printable drum set coloring page. Thereby stopping the wheel. These drum brake systems need adjustment too and in fact a parking brake that is too far out of adjustment can fail a state vehicle inspection. It is the frictional part of the drum brake without it the working of the brake is not possible.

Drum brakes have return springs to return the shoes to a rest position and hardware to hold the shoes to the backing plate. Many cars have drum brakes on the rear wheels and disc brakes on the front. There is no compensation for lining wear.

The shoes return to a fully retracted or rest position when the pressure to the wheel cylinder is released. Drum brakes unlike disc brakes have a self energizing ability that takes advantage of geometry to boost stopping power without increasing braking pressure. The friction material layer on a worn brake shoe can be replaced to allow for re manufacturing of the part.

The primary shoe tends to rotate with the brake drum which forces the secondary shoe against the brake drum surface. A drum brake is a brake that uses friction caused by a set of shoes or pads that press outward against a rotating cylinder shaped part called a brake drum. When shoes press on the outside of the drum it is usually called a clasp brake.

The secondary shoe is held in place by the anchor pin located at the top or bottom of the backing plate. The friction between the brake linings and the drum causes the drum to stop rotating. The brake shoe has brake lining at its outer curve.

Some vehicle with four wheel disc brakes still use a drum brake inside the rear rotors that acts as the parking brake. Drum brakes work on the same principle as disc brakes. The term drum brake usually means a brake in which shoes press on the inner surface of the drum.

Adjusting drum brakes correctly can be an art. When applied the wheel cylinder piston forces the primary shoe against the rotating brake drum surface. For the drum brakes to function correctly the brake shoes must remain close to the drum without touching it.

If they get too far away from the drum as the shoes wear down for instance the piston will require more fluid to travel that distance and your brake pedal will sink closer to the floor when you apply the brakes. In this system that surface is called a drum. This results in a gap between them and the drum and to again spin it freely.