|There are two primary types of brake chambers commonly used in air brake systems. One is called a spring brake chamber. This is actually two chambers sometimes called a "piggyback". One chamber operates the service brakes when the driver depresses the brake pedal or hand valve. The second chamber contains a very large and powerful spring. This spring is used to engage the brakes when the trailer is parked or in a break away situation.
The second type of commonly used chamber is a service only chamber. It is like a spring brake chamber minus the spring section. It depends on the service valve to provide air pressure for brake force during service application, park and/or emergency modes.
Air systems (and the valves) must be designed specifically for each chamber type to accommodate stopping, park and emergency requirements. The Technical Section contains more information regarding the different systems.