This type of brakes uses one or two small air chambers with wedge-shaped pushrods. Most wedge brakes have internal automatic adjusters.
Knowledge test Question: how many brake chambers can a wedge brake have:

Answer; 1 or 2.

Wedge brakes must be checked and adjusted by a qualified mechanic.

The driver can look for damaged and insecure components. The tug tests will also reveal if the brakes are working properly.

Again: these types of brakes are rare. These can be identified because the the brake chamberand push-rod are facing the wheel assembly.