2-11. FIREFIGHTING OPERATIONS-Continued
Turn the foam metering valve (12) to required foam percentage.
Set the foam valve switch (13) to OPEN.
While discharging foam, observe the water and foam tank level gages (14 and 15). Reduce the engine
speed to idle before or immediately after the water tank is emptied and shut the pump OFF.
If the engine water temperature exceeds 210 deg. F (100 deg C), open COOLER valve (9) until
If the foam tank is emptied, firefighting may be continued using water only. Set the foam valve
and water eductor switches to CLOSED and set the foam proportioning valve to 0.
When backing off the throttle bring the, engine to an idle, then back the throttle control off an
additional three turns. This will prevent the throttle control from interfering with the governor
control when in the CFR mode. Failure to adhere to this procedure will cause excessive
hydraulic hammering resulting in catastrophic damage to the water delivery system.
When the fire is extinguished or the water supply is emptied, throttle the engine back to idle and close all
Set the pump switch (5) to OFF.
If the pump cannot be disengaged with the switch, open the manual pump shutdown valve (16).
If required, set the water tank valve switch (4) to OFF
If foam has been used, set the foam valve (13) and water eductor switches (10) to CLOSED and turn the
foam metering valve (12) to 0.
If the hose reel has been used, open the hose nozzle and blow air through the hose to remove residual
water. Rewind the hose (see para. 2-5).
Disconnect and store other hoses as applicable and cap all suction and discharge ports.
Change 4 2-54