The air applied model 5040-A is a pneumatically operated caliper requiring only an air supply and a pressure regulator. The pressure regulator can be adjusted to provide the customer with the desired torque or stopping characteristics. Two air-on actuators consisting of a double diaphragm system provide an equal force to each brake shoe when an air pressure is applied. The action of compression springs return the caliper to the 'brake-off' position when the air pressure is shut off.

Caliper 5040-A is also avaliable in a mechanically applied model. A 5400 lb. pulling force is required to drive a wedge between the two brake arm levers thereby applying the brake.

Both types employ the balancing link which ensures equal wear on both linings.