2-13. FIREFIGHTING OPERATIONS-Continued
(5) Depress brake pedal and move truck transmission selector lever into D (drive).
Do not put truck transmission selector lever in R (reverse)
position. Damage to water pump will result.
If the green OK TO PUMP light does not illuminate, or a grinding
noise occurs, move the transmission selector lever back to N
(neutral) position, pause for several seconds and move the
selector lever to D (drive) position.
When pump is engaged, truck speedometer should indicate
approximately 18 MPH.
(6) Turn RELIEF VALVE lever to ON position and rotate INCREASE/DECREASE handle to obtain
desired pump output pressure.
(7) Open discharge valves slowly and accelerate engine with THROTTLE control on pump panel to
obtain desired discharge pressure and capacity.
Monitor engine coolant temperature. If the temperature exceeds
210 deg. F (99 deg. C), or the alarm sounds, open ENGINE
COOLER control valve gradually until temperature stabilizes at
200 deg. F (93 deg. C). Failure to heed this caution may cause
Do not attempt to pump more water than is available from
hydrant or relaying pumper. Always make sure compound-
gauge reading stays above zero. Some fire departments
operate at a minimum suction pressure of 1O psi (69 kPa) when
pumping from a hydrant or in relay to prevent a "soft" suction
hose from collapsing.
Priming the Pump.
(1) Start the engine (see para 2-12).
(2) Engage the water pump transmission (see para b. above).
Do not run the primer motor for longer than 30 seconds. Stop
priming operation and allow priming motor to cool for 1 minute
before operating primer again. Damage to primer motor may