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MAXIM 50R-X12 PUMP OPERATION / MAINTENANCE MANUAL
5
TROUBLESHOOTING
Pump Will Not Start, Fails to Operate
Cause:
Solution:
Insufficient air pressure.
Must be minimum 20 psig at pump air hook-up.
Insufficient air volume (low supply
pressure during running).
See Performance Charts (3.1) for requirements. Check
for both regulator and control valve capabilities.
Fluid discharge line blocked.
Downstream valve closed, filter plugged
or other obstruction.
Remove obstruction.
Pilot valve failure.
Inspect and replace pilot valve body and poppet.
Detent failure.
Inspect detent legs for worn or damaged parts.
Bubbles in Fluid Discharge
Cause:
Solution:
Leaking fluid inlet fitting.
Replace adapter seal.
Leaking main seal.
Tighten union nut to 75 ft-lbs. or replace diaphragms, and
check head and body seal grooves for nicks or scratches.
Pump inlet line pressure reached
saturation point (due to high suction
requirement).
Increase diameter of suction supply line (reduces
restriction).
Reduce output flow.
Ruptured (perforated) diaphragm.
Replace diaphragms.
Check bore caps leaking.
Tighten check bore caps or replace seals.
Fluid Leaks
Cause:
Solution:
Union nut torque not enough to effect
seal.
Tighten union nuts to 75 ft-lbs.
Leaking main seal.
Replace diaphragms.
Check head and body seal grooves for nicks or scratches.
Check bore cap.
Tighten, or remove and replace seal.
Ruptured diaphragm(s) can result in
fluid leaks through air exhaust port.
Replace diaphragms, and any parts that may have been
damaged by fluid exposure.
Erratic Cycling
Cause:
Solution:
Pilot valve failure.
Inspect and replace pilot valve body and poppet.
Suction line restricted (cavitation).
Reduce fluid restriction(s).
Detent failure.
Inspect and replace spool assembly.
Check ball(s) not seating.
Check O-rings for damage; replace if necessary.
Make sure check balls move freely in sleeves.
Over pressurization of pump discharge.
Reduce discharge pressure by removing restriction.
