Hale MG - Manual (Page 62)

Muscle Pumps
4-4
CONDITION POSSIBLE CAUSE SUGGESTED CORRECTION
INSUFFICIENT PUMP
CAPACITY Insufficient engine power
Transfer Valve not in proper
“Volume” position
Relief Valve improperly set
Engine Governor set
incorrectly
Truck transmission in wrong
gear or clutch is slipping
Air Leaks Engine power check or tune up may be
required for peak engine and pump
performance.
TWO STAGE PUMPS ONLY. Place
transfer valve in “Volume” position (parallel)
when pumping more than 1/2 rated capacity.
For pressure above 200 PSI (13.8 BAR),
pump should be placed in “Pressure” (series)
position.
If relief valve control is set for too low a
pressure, it will allow relief valve to open and
bypass water. Reset Relief Valve control per
the procedures in Section 3. Other bypass
lines (such as foam system or inline valves)
may reduce pump capacity or pressure.
Engine governor, if set too low a pressure
when on automatic, will decelerate engine
speed before desired pressure is achieved.
Reset the governor per manufacturer’s
procedures.
Recheck the pumping procedure for the
recommended transmission or gear range; see
Section 3 for assistance.
Use mechanical speed counter on the pump
panel to check speed against possible clutch
or transmission slipping or inaccurate
tachometer. (Check the truck manual for the
proper speed counter ratio).
See air leaks under “PUMP LOSES PRIME
OR WILL NOT PRIME”.
INSUFFICENT
PRESSURE Check similar causes for
insufficient capacity
Transfer Valve not in
“Pressure” position Recheck pumping procedure for
recommended transmission gear or range. Use
mechanical speed counter on pump panel to
check actual speed against possible clutch or
transmission slippage or inaccurate
tachometer. (Check the truck manual for
proper speed counter ratio).
TWO STAGE PUMPS ONLY. For desired
pump pressure above 200 PSI (13.8 BAR),
transfer valve should be in “Pressure”
position.