Hydraulic Pump - Yale 524150797 Maintenance Manual

1900 YRM 1506
PROBLEM
Rod spontaneously retracts.
Wear limit (clearance between cylin-
der tube and wear ring).

HYDRAULIC PUMP

PROBLEM
Pump not delivering oil.
Pump pressure fails to rise.
POSSIBLE CAUSE
Scores on inner surface of tube.
Score on tube.
Score on piston ring.
Foreign matter on packing ring.
Considerable score on lip of pack-
ing ring.
Unusual distortion of packing ring.
Excessive clearance between cyl-
inder tube and wear ring.
POSSIBLE CAUSE
Pump does not draw oil.
Low oil level in reservoir.
Clogged screen at pump inlet.
Improperly adjusted relief valve.
Relief valve clogged.
Interfering relief valve or broken re-
lief spring.
Air suction.
Troubleshooting
PROCEDURE OR ACTION
Smooth surface with an oil stone.
Replace cylinder tube.
Replace piston ring.
Replace packing.
Replace packing.
Replace packing.
Replace wear ring (included in
packing kit).
PROCEDURE OR ACTION
Check pump, piping, and valves
for leaks.
Check fluid level.
Change oil and clean screen.
Increase to specified pressure us-
ing a pressure gauge.
Disassemble and clean with fresh
oil.
Disassemble valve and replace
spring.
Check piping on suction side for
leaks.
Add oil to reservoir.
Check pump seals.
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