9
TROUBLE
PROBABLE CAUSE
REMEDY
Pump not delivering oil
Driven in wrong direction of rotation.
Pump drive shaft disengaged or sheared.
Flow control valve stuck open.
Check direction of pump shaft rotation. It
should rotate clockwise as viewed from the
coupling end of the unit.
See also reassembly instructions for pump
cartridge.
Remove pump. Determine damage to
cartridge parts (see disassembly
instructions). Replace sheared shaft and
needed parts.
Disassemble pump and wash control valve
in a clean solvent. Return valve to its bore
and slide it back and forth. No stickiness in
movement should occur. If a gritty feeling is
noted on the valve O.D. it may be polished
with a crocus cloth. Avoid removal of excess
material or rounding of valve edges during
this operation. Do not attempt to polish the
valve bore. Wash all parts before
reassembly of pump. Fill system with clean
oil per prescribed recommendations.
Pump not delivering oil (Con’t)
Vane or vanes stick in rotor slots.
Oil viscosity too heavy to pick up prime.
Disassemble pump. Examine rotor slots for
dirt, grime or small metal chips. Clean rotor
and vanes in a good grade solvent (mineral
oil or kerosene). Reassemble parts and
check for free vane movement.
Use fluid of the proper viscosity as
recommended in oil data (Table 3).
Noisy pump operation
Pump intake partially blocked.
Air vent for oil tank clogged or dirty
strainer.
Air being drawn into pump return
connection.
Leaking shaft seal.
Drain system completely. Flush to clear
pump passages. Flush and refill system
with clean oil as per prescribed
recommendations.
Remove filler cap and clean air vent slot.
Check strainer in tank for clogged
condition. Drain, flush and add clean oil to
system.
Pump must receive air-free oil or pump will
be noisy. Drain system. Tighten all hose
connections. Clean or replace filter. Add
clean oil of the proper viscosity.
Check pump shaft seal and replace if
sealing lip has been damaged. Check for
scoring of shaft at seal contact area.
Replace faulty shaft.
Table 4. Troubleshooting Chart
