Swing Pumps Circuit
FAILURE OF PUMP TO DELIVER FLUID
CAUSE REMEDY
Pumps not engaged Engage pumps
Low fluid level in reservoir Add recommended oil and check level
Oil intake suction filter plugged Clean filter
Air leak in suction line, preventing priming or
causing noise and irregular action of control
circuit
Repair leaks
Oil viscosity too heavy to pick up prime Use lighter viscosity oil. Follow
recommendation for temperatures
encountered
Broken pump shaft or parts broken inside
pump
Contact your local distributor; if necessary,
refer to the manufacturer’s manual for the
correct instructions in pump disassembly
and repair
NO PRESSURE IN SYSTEM
CAUSE REMEDY
Pumps not engaged Engage pumps
Pump not delivering oil for any of the
reasons listed previously
Follow remedies given previously
Relief valve not functioning due to:
Valve setting not high enough Increase pressure setting of valves
Valve leaking Check seat for score marks and reseat
Spring in relief valve broken Replace spring and readjust valve
Internal leakage in control valves or cylinders To determine location, progressively block
off various parts of circuit. When trouble is
located, repair. (Do not block between pump
and relief valve)
Relief valve not functioning due to:
Cold fluid Warm up system. Work with oil at
recommended operating temperature range.
(See Operation section)
Air leak or restriction at inlet line Repair or clean
Internal parts of pump are worn excessively Replace pump
411P/N 12261-683 REVISED: January 2015
To Next Page
Loading...
