Trebor 620R Magnum - Manual (Page 26)

PAGE 26 MAGNUM 620R PUMP OPERATION / MAINTENANCE MANUAL
5 TROUBLESHOOTING
Pump Will Not Start, Fails to Operate
Cause: Solution:
 Insufficient air pressure.  Must be minimum 12 psig at pump air hook-up.
If check muffler spring assembly is installed at high
setting, start pressure may be up to 35 psi.
 Insufficient air volume (low supply
pressure during running).  See Performance Charts (3.1) for requirements. Check
for both regulator and control valve Cv’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 effect seal.  Remove heads and allow 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:
 Fluid supply inlet pressure too high.  Adjust check muffler per Section 1.3.
 Pilot valve failure.  Inspect and replace pilot valve body and poppet.
 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.