TEST OR INSPECTION
Air lines may be under pressure when shutoff control valve manifold is operated. If
under pressure and air lines are disconnected, air lines may whip around and cause
injury to personnel. Caution should be exercised when operating control valve with
air lines disconnected. Failure to comply may cause injury to personnel.
Air pressure is checked by disconnecting air lines at driver side tank-to-pump valve and
observing air pressure escaping from air lines. Air will escape from blue air line when
TANK TO PUMP switch is put to on position (WP 0004), and escape from red air line when
TANK TO PUMP switch is put to off position (WP 0004). System air pressure may drop
below 85 psi (586 kPa) during this procedure.
Disconnect red and blue air lines from two elbows. While an assistant puts cab or pump
operator's panel TANK TO PUMP switch to on position (WP 0004), check if air pressure
is present at blue air line.
If there is air pressure, replace driver side tank-to-pump valve (WP 0493).