PUMP-ELEC/HYD 6V4850 - Caterpillar

Illustration 1 g00526860
Location of the retarder air control valve
Illustration 2 g00526861
Bottom view of the retarder air control valve
(1) Outlet port
(2) Exhaust port
(3) Supply port The retarder air control valve is a hand operated control valve. When the operator needs to retard the machine, the retarder air control valve provides modulated air supply in order to apply the service brakes. Air supply from the air tank for the service brake and the retarder flows into supply port (3). When the retarder hand control lever is moved out of the OFF position, the retarder air control valve allows air from supply port (3) to flow through outlet port (1). The position of the retarder hand control allows the valve to modulate the outlet pressure that flows to the brake air relay valve. When the retarder hand control lever is in the OFF position, air at system pressure at the supply port (3) is blocked from outlet port (1). When the retarder hand control lever is released, the air pressure is discharged through exhaust port (2).