15
Troubleshooting Chart
・
If you experience no oil discharge, a high pitched sound, or such other abnormal
phenomena soon after the installation, check the troubleshooting chart in the
table that follows. If you cannot find out the cause of trouble, consult us or your
dealer.
Pump Troubleshooting Chart
Symptom
Possible causes
Check methods
Possible remedies
Insufficient flow
or pressure.
Pump doesn’t
draw oil.
Discharge amount
is insufficient or no
oil discharge.
・
Measure the suction pressure
with vacuum gauge, the suction
pressure lower than -0.03MPa
may cause cavitation.
・
Replace the oil with lower
viscosity.
・
Check for suction pipe
clogging
.
Check out the suction filter if it’s
clean.
・
Clean out the suction filter.
・
Not enough oil in the tank.
・
Check the oil level with level
gauge or make a visual check.
・
Fill the tank with oil up to the
specified level.
Guide line: The amount of oil
which is 3-4 times larger than
the pump flow rate.
・
Is the pump drawing air from
the pipe joints?
・
Retighten the pipe joints.
・
Viscosity of oil is too low for the
intended pressure.
・
Change the viscosity of oil to
the suitable level for your
pump.
・
Tighten up the relief valve
pressure control screw while
referring to the pressure gauge
.
Result : Pressure won’t build up.
・
Clean out the relief valve or
remove foreign object as
something might get stuck in
the relief valve.
・
Tighten up the relief valve
pressure control screw while
referring to the pressure gauge.
Result : Pressure builds up.
・
Set pressure is too low. Raise
the set pressure as oil is
leaking through the relief valve.
・
The pump is rotating backward.
・
Visual check of rotation
direction.
・
Change the direction of rotation
as indicated on the pump.
・
Is suction line or discharge line
blocked?
・
Release the suction line and
discharge line.
・
Widen the diameter of suction
pipe or discharge pipe.
Oil leaks.
Oil leaks from oil
seal.
・
Is the pump rotating in correct
direction?
・
Repair or replace pump.
・
Is suction pipe pressurized?
・
The pump should be mounted
at a position higher than oil
surface level.
・
Pressure resistance of oil seal
must be within the range of 0
~
0.03MPa.
・
If check valve (NRV) is installed
in the suction line, pressure
may be trapped inside the
discharge line and as it has
nowhere to go, the whole
pressure will be applied on oil
seal area.
・
Oil temperature exceeds
maximum resistance
temperature of oil seal.
・
Oil seals for special materials
also can be supplied if
requested.
・
Oil is incompatible with oil seal
materials.
・
Replace seal or pump.
