Model 30000-S DHPU Manual
Rev. 0
JRK
17SEP12
Page 25
generated from the pump if the bearings are worn or
damaged. Rebuild or replace the pump.
Reservoir level gauge or
pressure gauge is showing
contamination
1) If the ambient temperature is low, then warm up the
power unit to raise the hydraulic fluid temperature and
lower the viscosity.
2) Inspect the return filter element. Replace if it is
contaminated.
3) Take a sample from the tank drain port. If
contaminated, then replace the hydraulic fluid in the tank
after cleaning the tank's interior.
Hydraulic fluid temperature is
too high
1) Verify the correct viscosity of hydraulic fluid is being
utilized for the operating temperature. Change fluids if
necessary.
2) Inspect the heat exchanger fins, and clean if clogged
with debris. Verify the fan motor is spinning.
3) Inspect the fluid level of the hydraulic reservoir. If the
level is below the sight glass, then add hydraulic fluid.
4) Inspect the hydraulic system for an excessive pressure
drop, which could be caused by any of the following.
a) Verify the quick disconnects are completely
tightened and engaged.
b) Inspect the return filter pressure gauge. Replace
the filter elements if required.
c) Ensure the hoses are adequate for the power unit
flow (1" for pressure, 1-1/4" for return).
5) Ensure the power unit is connected to an open
centered valve not a closed center valve.
Tong torque is low
1) Verify the setting of the pressure relief valve (RV-1) is
not set too low. Adjust to the desired pressure. Increase
the valve setting while applying torque to the joint.
2) Inspect the pressure gauge for correct operation.
Check the tong torque output against a tension type tong
torque gauge if available.
3) If the hydraulic pump is damaged, then rebuild or
replace the pump.
Tong rotates slowly
1) If the flow rate seems low, then make sure the
hydraulic throttle is operating as designed.
2) Inspect the hydraulic system for an excessive pressure
drop, which could be caused by any of the following.
a) Verify the quick disconnects are completely
tightened and engaged.
b) Inspect the return filter pressure gauge. Replace
the filter elements if required.
c) Ensure the hoses are adequate for the power unit
flow (1" for pressure, 1-1/4" for return).
