Remedy:
Replace the shaft seal following disassembly and
assembly steps outlined in the Maintenance and Repair
Manual. Check the shaft seal. It should have a spring
installed inside and around the shaft sealing lip.
4.1.9 Possible Cause
Exhaust valve (Ref. 159) is not properly seated or it is
partially stuck open (RA models only).
Remedy:
Follow disassembly and assembly steps outlined in the
Maintenance and Repair Manual.
4.1.10 Possible Cause
The vanes are blocked in the rotor or are otherwise dam-
aged.
Remedy:
Free vanes or replace with new ones following disas-
sembly and assembly steps outlined in the Maintenance
and Repair Manual.
4.1.11 Possible Cause
Radial clearance between the rotor and cylinder is no
longer adequate.
Remedy:
Follow disassembly and assembly steps outlined in the
Maintenance and Repair Manual on resetting the radial
clearance correctly.
4.1.12 Possible Cause
Internal parts worn or damaged.
Remedy:
Follow disassembly and assembly steps outlined in the
Maintenance and Repair Manual and replace worn or
damaged parts.
4.2 Trouble
Pump will not start.
4.2.1 Possible Cause
Motor does not have proper supply voltage or is over-
loaded; motor starter overload settings are too low or
wrong setting; fuses are burned; or wire is too small or
too long, causing a voltage drop to the motor.
Remedy:
Check correct supply voltage; check overload settings in
motor starter for size and setting according to motor
nameplate data; check fuses; and install proper size
wire. If ambient temperature is high, use larger size over-
loads or adjust setting 5% above nominal motor name-
plate value.
4.2.2 Possible Cause
Pump or motor is blocked.
Remedy:
Remove fan cover and try to turn pump and motor by
hand. If frozen, remove motor from pump and check
motor and pump separately. If pump is frozen, disas-
semble completely per the Maintenance and Repair
Manual and remove foreign objects in the pump or
replace broken vanes.
4.3 Trouble
Pump starts, but labors and draws a very high current.
4.3.1 Possible Cause
Oil too heavy (viscosity too high) or ambient temperature
below 5 degrees C (41
°
F).
Remedy:
Change to R580 vacuum oil if very cold, or warm up oil
before starting the pump.
4.3.2 Possible Cause
Pump runs in the wrong direction.
Remedy:
Check for correct rotation which is counterclockwise
when looking at the motor from the motor's fan side.
4.3.3 Possible Cause
Pump is overfilled with oil or the wrong kind of oil is used.
Remedy:
Correct the oil level and quality per Section 1.5 and use
recommended motor oil.
4.3.4 Possible Cause
Exhaust filters in exhaust chamber are clogged and
appear burned black with pump oil.
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