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Revision B December 2013
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Pump Priming
1. New
Assemblies
New system assemblies, as well as those that are disassembled for repair, require
proper priming to avoid possible pump failure. A pump is said to be ''primed'' when the
internal cavity is full of oil and all air has been expelled.
A. Prime a pump as follows:
1. ''Crack'' or remove the high pressure line at or near the cylinder.
2. ''Jog'' the unit until oil flow is clear.
3. Retighten or replace hose.
2.
When Systems Fail to Prime or Lose Their Prime, Check for the Following:
A. Correct unit mounting position in the case of a pump-motor-reservoir combination. It is
either horizontal or vertical and failure to mount in the proper manner could mean pump
could not prime (pick up oil) because the suction is not submerged in the oil at all times.
Note: Pumps designed for vertical mounting will have a label stating such.
B. Partially clogged suction filter (see Filter section).
C. A loose or improperly assembled suction hose or pickup tube.
D. A bad front pump seal (see Pump section).
E. A solid fill plug in reservoir with no vent (see Reservoir section).
F. Oil that is too thick (see Hydraulic fluid section) or contaminated with water (see
Reservoir section).
G. Occasionally a pump will not prime itself because a check valve spring in the high
pressure port is too “stiff” or the Spring Retainer is turned down too far. If this condition is
expected, loosen the Spring Retainer (found in the high-pressure outlet port), energize
the pump to prime it, and then turn the retainer back to the correct depth (see section on
Check Valves).
Reservoirs
1.
Use Recommend Fluid
Fill reservoir with Dexron
®
III ATF (see Hydraulic Fluid section).
2.
Filling & Operating
A. Fill reservoir to within 12.5 mm [1/2''] with all the cylinders in the fully retracted
position.
B. Operate unit several times starting with short cylinder strokes and increasing length of
each successive stroke.
C. Re-check oil level often and add as necessary to keep pump from pulling in air.
D. After system is purged of air, collapse all cylinders, check oil level in reservoir, and
assemble the filter/breather plug provided.
Note:
Do not use a solid plug or fill cap without a filter breather element, or damage will
be caused to the pump and/or reservoir.
3. Reservoir
Problems
