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| Illustration 1 | g00509758 |
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Location of the pulled unit air control valve | |
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| Illustration 2 | g00497252 |
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(1) Outlet port
(2) Exhaust port (3) Supply port | |
The pulled unit air control valve is a hand operated control valve. When the operator needs to retard the pulled unit, the pulled unit air control valve provides modulated air supply in order to apply the brakes on the pulled unit. Air supply from the primary air tank flows into supply port (3). When the hand control lever for the pulled unit is moved out of the OFF position, the pulled unit air control valve allows air from supply port (3) to flow through outlet 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 (3) is blocked from outlet port (1). When the hand control lever for the pulled unit is released, the air pressure is discharged through exhaust port (2).