Greenlee WW 980 Manuel D'instructions page 11

Troubleshooting—Hydraulic Pump (cont'd)
Ram will not advance.
Ram advances slowly.
Ram will not advance
completely.
Ram advances erratically
and retracts erratically.
Greenlee Tools, Inc.
Low-pressure system has a partial
or complete failure.
Unvented plug has not been
replaced.
Oil level is too low.
Wrong oil viscosity.
Oil is dirty.
Oil is cold.
The intake strainer is dirty or
clogged.
Motor rotates in the wrong
direction.
Low-pressure relief valve is dirty or
is set incorrectly.
Broken internal part.
Worn or damaged internal part.
Pilot-operated valve will not close.
Internal hydraulic fluid leak.
Air in the hydraulic fluid.
980 Hydraulic Power Pump
See Hydraulic Schematic (1, 3, 7) and refer to
Figure A4 in the Repairs section of this manual.
Remove the unvented plug and install the vented
plug.
Add oil per instructions in the Maintenance
section of this manual.
Replace oil with the type recommended in the
Specifications section of this manual.
Replace oil with the type recommended in the
Specifications section of this manual.
Preheat oil. Without an accessory connected to
the coupler, run the pump to build pressure, then
release. Repeat until oil is warm.
Remove the strainer and clean with kerosene.
Correct the motor wiring. See the Motor Control,
Schematic Diagram in the Motor Control Unit
section of this manual.
To clean and adjust this valve, see Low-Pressure
Relief Setting, Figure A4 in the Repairs section of
this manual.
Inspect and/or replace drive pin (78), motor shaft
key (34), rollpin (39), or drive shaft (77).
Inspect and/or replace the gerotor (80); eccentric
shaft (38), or bearings (37 and/or 41).
See Troubleshooting—Pilot-Operated Valve at the
end of this troubleshooting section.
Inspect and replace as necessary: O-ring Plug (79)
and Pump Block Cover (50).
Refer to Purging (Bleeding) Air in the Maintenance
section of this manual.
11
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