Troubleshooting - Greenlee 975 Instruction Manual

Troubleshooting—Hydraulic Pump (cont'd)
Problem
Ram will not advance.
Ram advances slowly.
Ram will not advance completely.
Greenlee Tools, Inc.
Probable Cause
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.
11
975 Hydraulic Power Pump
Probable Remedy
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 and Service section of
this manual.
Replace oil with the type recom-
mended in the Specifications section
of this manual.
Replace oil with the type recom-
mended in the Specifications section
of this manual.
Preheat oil. Without an acces-
sory 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).
4455 Boeing Dr. • Rockford, IL 61109-2988 USA • 815-397-7070