11
Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
Pump not delivering fluid
Driven in the wrong direction of rotation
The drive direction must be changed
immediately to prevent seizure. Figure 9
shows the correct ring position for each
direction of rotation.
Coupling or shaft sheared or
disengaged.
Disassemble the pump and check the
shaft and cartridge for damage. (See
Section VI.) Replace the necessary
parts.
Fluid intake pipe in reservoir restricted
Check all strainers and filters for dirt and
sludge. Clean if necessary.
Fluid viscosity too heavy to pick up
prime.
Completely drain the system. Add new
filtered fluid of the proper viscosity.
Air leaks at the intake. Pump not priming
Check the inlet connections to
determine where air is being drawn in.
Tighten any loose connections. See that
the fluid in the reservoir is above the
intake pipe opening. Check the
minimum drive speed which may be too
slow to prime the pump.
Relief valve stuck open. (Models with
integral relief valve only)
Disassemble the pump and wash the
valve in clean solvent. Return the valve
to its bore and check for any stickiness.
A gritty feeling on the valve periphery
can be polished with crocus cloth. Do
not remove excess material, round off
the edges of the lands or attempt to
polish the bore. Wash all parts and
reassemble the pump.
Vane(s) stuck in the rotor slot(s)
Disassemble the pump. Check for dirt or
metal chips. Clean the part thoroughly
and replace any damaged pieces. If
necessary, flush the system and refill it
with clean fluid.
Insufficient pressure build-up
System relief valve set too low
Use a pressure gage to correctly adjust
the relief valve.
Worn parts causing internal leakage of
pump delivery
Replace pump cartridge.
Pump making noise
Pump intake partially blocked
Service the intake strainers. Check the
fluid condition and, if necessary, drain
and flush the system. Refill with clean
fluid.
Air leaks at the intake or shaft seal. (Oil
in reservoir would probably be foamy)
Check the inlet connections and seal to
determine where air is being drain in.
Tighten any loose connections and
replace the seal if necessary. See that
the fluid in the reservoir is above the
intake pipe opening.
Pump drive speed too slow or too fast
Operate the pump at the recommended
speed.
Coupling misalignment
Check if the shaft seal bearing or other
parts have been damaged. Replace any
damaged parts. Realign the coupled
shafts.
Figure 4. Troubleshooting Chart