TROUBLESHOOTING
Page 20 of 20
CONDITION
POSSIBLE
CAUSE
SUGGESTED REMEDY
Insufficient
capacity
Insufficient
engine power
Engine requires maintenance. Check engine in accordance with manufacturer's
instruction.
Pump impeller
or wear rings
badly worn
Check the wear hubs on the impeller for excessive wear, or clearance with the wear
rings. If the clearance exceeds 0.020/0.025 in., or if the impeller hubs are badly scored
or grooved, replace the impeller and both wear rings.
Intake strainer
or impeller
vanes fouled
with debris
Remove intake strainer and hose and clear away all debris. Pressure backwash will
usually clear impeller vanes when pump is stopped.
Intake hose
defective
On old intake hoses, the inner liner sometimes becomes so rough it causes enough
friction loss to prevent pump from drawing capacity. Sometimes, the liner will separate
from the outer wall and collapse when drafting. It is usually impossible to detect.
Intake hose
too small
When pumping at higher than normal lifts, or at high altitudes, use a larger intake hose.
Intake hose
too long
Position pump as near as possible to water supply.
Insufficient
pressure
(In general,
the above
causes and
remedies for
insufficient
pump capa
city will also
apply to
insufficient
pump
pressure.)
Engine speed
too low
Check engine speed with a tachometer. If speed is too low, refer to engine
manufacturer's instructions for method of adjusting engine speed control.
Pump capacity
limits pump
pressure
Do not attempt to pump greater volume of water at desired pressure than the pump is
designed to handle. Exceeding pump capacity may cause a reduction in pressure.
Exceeding maximum recommended capacity will produce cavitation, and will seriously
impare pump efficiency. When pumping from water tank, hydrant or relay, always make
sure the intake pressure gauge reading stays above zero.
