PUMP- 2389316 - Caterpillar

Illustration 1 g01198513
Brake air relay valve
(1) Brake air relay valve for service brakes and for manual retarder Brake air relay valve (1) receives signal pressure when the service brake pedal is pushed or when the manual retarder is used.When the brake pedal is pushed or when the manual retarder is used, signal pressure is sent to the control passage of the brake air relay valve (1). This causes an internal valve in brake air relay valve (1) to open. This allows air from the primary air tank to flow through the brake air relay valve (1). This air flows to the air chambers of the brake master cylinders. The brake master cylinders then engage the brakes.When the brake pedal is released or when retarding is not needed, the signal pressure to the control passage of brake air relay valve (1) will stop. The internal valve in the brake air relay valve will shift in order to block the flow of air from the primary air tank. When the brake master cylinders do not receive air flow to the air chambers, the brakes are released.