MAGNUM 620D PUMP OPERATION / MAINTENANCE MANUAL
PAGE 37
5 TROUBLESHOOTING
Pump Will Not Start, Fails to Operate
Cause:
Solution:
•
Insufficient air pressure.
•
Must be minimum 28 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 C
v
s >.85 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.
•
Tighten fittings or replace adapter seal.
•
Leaking main seal.
•
Tighten heads an additional 15
°
.
Replace diaphragms, and check head and body 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:
•
Head torque not enough to affect seal.
•
Remove heads and allow them to sit for 1 hour.
Reassemble with new diaphragms.
•
Leaking main seal.
•
Replace diaphragms.
Check head and body seal grooves for nicks and
scratches.
•
Check bore cap.
•
Tighten, or remove and replace seal.
•
Ruptured diaphragm(s) can result in
fluid leaks through air exhaust port and
shuttle valve.
•
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 pilot.
•
Suction line restricted (cavitation).
•
Reduce fluid restriction
•
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 reducing restriction.
