FRAME AS-MAIN 3985807 - Caterpillar

BRAKESAVER CONTROL VALVE IN FLOW CONTROL POSITION
1. Passage to oil filter. 2. Oil cooler. 3. Air line. 4. Oil inlet passage. 5. Valve spool. 6. Control valve body. 7. Differential pressure valve. 8. Poppet valve. 9. BrakeSaver. 10. BrakeSaver inlet pressure. 11. BrakeSaver outlet pressure.BrakeSaver Operator Controls
Two types of controls are available for the BrakeSaver: a manual control and an automatic control. Supply air goes into the circuit through pressure reducing valve (17). The pressure reducing valve keeps a maximum pressure in the control circuit of 40 psi (280 kPa).This pressure air is available at manual control lever (2) in the operator's compartment and at the solenoid valve (8). When ignition switch (5) is turned ON, the electrical circuit to manual-automatic switch (3) has current available. [Switch (3) is shown in the MANUAL position.] In the MANUAL position, switch (3) opens the circuit. The automatic section of switch (3) is in the OFF position and the BrakeSaver can only be operated manually. Maximum supply air pressure from the air compressor (not shown) is 125 psi (860 kPa).
BRAKESAVER CONTROL CIRCUIT SCHEMATIC
1. Pressure reducing valve. 2. Manual control lever. 3. Manual-automatic selector switch. 4. Control valve. 5. Ignition switch. 6. Double check valve. 7. Accelerator switch. 8. Solenoid valve. 9. Clutch switch.Manual Control
When the BrakeSaver manual-automatic selector switch (3) is in the MANUAL position, the BrakeSaver can only be turned on by the operator by moving manual control lever (2). With control lever (2) in the BrakeSaver ON position, air goes through manual control lever (2) and double check valve (6) to control valve (4). A valve spool moves and the BrakeSaver gets oil. It holds this oil until manual control lever (2) is moved to the BrakeSaver OFF position. Air can go from control valve (4) to the atmosphere through manual control lever (2).The farther control lever (2) is moved toward the ON position, the higher the pressure of the air sent to the control valve. An increase in air pressure in the control valve causes an increase in the oil pressure in the BrakeSaver. An increase in the oil pressure in the BrakeSaver causes an increase in the braking force in the BrakeSaver. The operator can give modulation to the braking force in the BrakeSaver through the movement of control lever (2).An air pressure gauge gives the operator a relative indication of the air pressure being sent to the control valve. Through the use of the indication on the air pressure gauge in relation to engine rpm, the operator can get approximately the same braking effect from the BrakeSaver time after time. This lets the operator more easily control the desired wheel speed of the vehicle.An oil temperature gauge gives the operator an indication of the ability of the engine cooling system to control the heat in the BrakeSaver during its operation. If the gauge reads too HOT, move control lever (2) to the OFF position and use the service brakes to control the wheel speed of the