Hale 4DK Series User Manual

Page 18

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18

Manual p/n: 029-0020-79-0

4DK Series Pumps

SUGGESTED CORRECTIVE ACTION

CONDITION

POSSIBLE

CAUSE

PUMP LOSES
PRIME OR WILL
NOT PRIME -
continued

Air trapped in
suction line -
continued

Pump pressure too
low when nozzle is
opened

Air leaks

If trap in hose is unavoidable, repeated priming may be
necessary to eliminate air pocket in suction hose.

Prime the pump again and maintain higher pump pressure
while opening the discharge valve slowly.

Attempt to locate and correct air leaks.

The suction side relief valve can leak. Plug the valve outlet
connection and retest.

INSUFFICIENT
PUMP
CAPACITY

Insufficient engine
power

Relief valve improp-
erly set - if so
equipped

Engine governor set
incorrectly - if so
equipped

Truck transmission
is in wrong gear, or
clutch is slipping

Air leaks

Engine power check or tune up may be required for peak
engine and pump performance.

If the relief valve pressure is set too low it allows the valve to
open and bypass fluid.

Reset the relief valve pressure accordingly.

If the engine governor is set too low when on automatic, the
engine speed decelerates before the desired pressure is
reached.

Reset the governor per manufacturer's procedures.

Recheck the pumping procedures for the recommended
transmission or gear range. See truck manual 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 possible
speed counter ratio.)

See Possible Causes "Air leaks" under PUMP LOSES PRIME
OR WILL NOT PRIME, beginning on page 17.

INSUFFICIENT
PRESSURE

See previous section: Insufficient Pump Capacity.

ENGINE SPEEDS
TOO HIGH FOR
REQUIRED
CAPACITY OR
PRESSURE

Chart continued on

next page

Truck transmission
in wrong range or
gear

Check recommended procedures for correct transmission
selection. (See truck manual for assistance.)

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