KIT-RELIEF VALVE 7W1938 - Caterpillar

Illustration 1 g00511189The Traction Control System (TCS) uses the rear parking brakes to decrease the revolutions of a spinning wheel. The "Rear Parking Brakes" are spring actuated brakes and hydraulically released brakes. The TCS allows the tire with better underfoot conditions to receive an increased amount of torque. The TCS system is controlled by the Brake ECM.The Brake ECM monitors the drive wheels through three input signals. The Brake ECM monitors one signal from each drive axle and one signal from the transmission output shaft. The Brake ECM sends a signal to the selector valves and proportional valves when the spinning of a drive wheel is detected. The selector valves and the proportional valves consecutively actuate the brake of the affected wheel. When the ratio between the right axle and the left axle returns to 1:1 ratio, the Brake ECM will release the brake.The "Traction Control System" was formerly referred as the "Automatic Electronic Traction Aid (AETA)". The operation of the system has not changed. The main difference is the appearance of the electronic control module and the TCS is connected to the Cat data link. Cat® ET can now communicate with the TCS.A service brake switch provides an input signal to the TCS through the Cat data link.The service brake switch performs two functions:
1. The TCS stops all functions, when the service brakes or the retarder is ENGAGED .
2. The service brake switch provides an input signal that is required to perform a diagnostic test.