TEST OR INSPECTION
Ensure system air pressure is at least 85 psi (586 kPa) when operating under truck nozzle
foam metering valve during this procedure. System air pressure is required to activate
Do not engage water pump engine during this procedure. Valve operation can be checked
without water pump operation.
Valve operations can be checked by observing valve shaft rotation. Valves are open when
tabs or yellow paint tabs are aligned with direction of fluid flow.
Operation of multi-metering valve cylinder can be checked by listening for metallic click.
Put TANK TO PUMP switch to closed position (WP 0004). If system air pressure is
below 85 psi (586 kPa), start vehicle engine and allow system air pressure to build to at
least 85 psi (586 kPa) (TM 9-2320-347-10). Shut off vehicle
engine (TM 9-2320-347-10). Open pump house panel A (WP 0539). Put cab FOAM
SYSTEM switch to on position (WP 0004). Put cab FOAM SELECT switch to A
position (WP 0004). While an assistant puts GROUND SWEEPS switch to on
position (WP 0004), check if ground sweeps foam A metering valve cylinder operates to
If ground sweeps foam A metering valve cylinder does not operate to open
position, troubleshoot Ground Sweeps Do Not Operate When Selected