ELECTRONICS AR-MACHINE 4370301 - Caterpillar

Illustration 1 g00648913
Location of the air control valve for the pulled unit
Illustration 2 g00641024
(1) Delivery port (2) Supply port (3) Exhaust portThe air control valve for the pulled unit is a hand operated control valve. When the operator needs to retard the pulled unit, the air control valve provides modulated air supply in order to apply the brakes on the pulled unit. Air supply from the service brake and retarder air tank flows into supply port (2). When the hand control lever for the pulled unit is moved out of the OFF position, the air control valve allows air from supply port (2) to flow through delivery port (1). The position of the hand control for the pulled unit allows the valve to modulate the outlet pressure that flows to the brake air relay valve. When the hand control lever for the pulled unit is in the OFF position, air at system pressure at the supply port (2) is blocked from delivery port (1). When the hand control lever for the pulled unit is released, the air pressure is discharged through exhaust port (3).