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TROUBLESHOOTING
NOTICE:
Maintenance shall be performed by qualified technicians only,
following the appropriate procedures and warnings as presented in this manual.
LEAKAGE
Location
Probable Cause/Corrective Action
Between the head & cylinder
Damaged head O-ring: Inspect and replace if necessary.
Burrs/dirt in head O-ring groove or cylinder: File and clean as
necessary.
Around the shaft
New Mechanical Seals: New seals may leak slightly at start up, but
should seal up shortly thereafter.
Damaged mechanical seals: Check for damaged O-rings or cracked,
scratched or worn seal faces
SHAFT BINDING
Probable Cause
Corrective Action
Burrs, dirt or foreign particles on the heads.
During assembly, both heads must be clean and smooth. File any burrs
or rough spots, and wipe the heads with a clean cloth and alcohol to
remove any dirt or foreign particles.
Other possible causes of shaft binding --------------------------------------------------------------------------------------------------
• Foreign particles on rotor or vanes.
• Damaged vanes or rotor.
• Bent push rods.
• Liquids that "set up" when inactive.
OVERHEATING
Location
Probable Cause/Corrective Action
Internal relief valve.
Continual, full bypassing of the liquid:
Properly adjust the relief
valve so that the pump will not bypass during normal operation.
WARNING: Internal bypassing of liquid elevates the liquid
temperature. Only use the internal bypass valve for brief periods
and at differential pressures below 125 psi.
For extended periods of higher pressures, the internal bypass
port must be plugged and the liquid returned back to the source.
Other possible causes of overheating ----------------------------------------------------------------------------------------------------
• Improper relief valve adjustment
(See "Relief Valve").
• Plugged discharge line.
• Closed valve.
LOW DELIVERY RATE
Probable Cause
Corrective Action
Relief valve setting too low, causing the liquid to bypass. Set the relief valve 20 psi (1.4 bar) higher than the differential pressure.
Other possible causes of a low delivery rate -------------------------------------------------------------------------------------------
Restriction in the suction line.
Resistance in the discharge line.
Air leaks in the suction line.
Damaged or worn pump parts.
Vanes installed incorrectly (see Vane Replacement)
Pump speed too low or too high.
Relief valve leaking.
Relief valve sticking open, or not properly seating.
Dirty
strainer.
