Brake Chamber

Brake Chamber Tech Info

Service Brake Chambers

The service brake chamber is used when only the application of service brake air is required on an axle. There will be no emergency braking provided on this axle. You will find service brake chambers on steer axles, some rear axles, and old trailers that use a relay emergency valve to apply parking air pressure to the service chamber.

Spring Brake Assembly

The spring brake assembly consists of the service brake and parking/emergency brake. The service brake is the section at the clamp closest to the axle. The diaphragm, pushrod and return spring may be serviced by removing the clamp. The spring/emergency brake is everything from the first clamp to the end farthest from the axle. The spring brake must be completely replaced if it is faulty.

How Spring Brakes Function

The spring brake assembly is bolted to a mounting bracket on the axle. The spring brake pushrod clevis is attached to a slack adjuster which is attached to a camshaft. As the spring brake pushrod is extended from the chamber, either by the parking/emergency brake or by service air pressure, the linear force of the pushrod is converted to rotational force by the slack adjuster and camshaft. This spreads the brake shoes against the brake drum.

When air is applied to the parking/emergency brake, the load of the heavy spring is released allowing the wheels to turn. When the driver steps on the brake pedal, a signal is sent to a relay valve that then sends air pressure to the service chamber of the spring brake. The air pressure causes the pushrod to extend which in turn applies the brake. This air pressure is released once the driver takes his or her foot off of the brake pedal.

The spring brake is designed to apply the the brakes automatically in the event that there is a loss of system air pressure. This happens because the air pressure holding back the heavy parking/emergency spring dissipates allowing the spring to extend the pushrod which in turn applies the brake.

In a truck air brake system the air brake chamber plays a vital role in the safety of a truck. Our BUENO Brake Chambers convert the energy of compressed air into mechanical force and motion. Through the air brake chamber's connection to a slack adjuster and then to a brake camshaft, this force and motion actuates the brake camshaft. The camshaft is twisted between the brake shoes, separating them to creacte friction inside the air brake drum. This friction causes the wheel to slow and stop the wheel and the vehicle. BUENO Brake Chambers are available in several sizes, providing a wide range of output forces and strokes.