Haskel 8 Serie Instructions De Fonctionnement Et D'entretien page 15

7. Troubleshooting Guide
7.1 Symptom
Drive will neither start nor cycle
with at least 25 psi drive
pressure.
Drive will not cycle under load
and pilot vent leaks air
continuously.
Drive will not cycle.
Mufflers leak drive air with very
audible "hiss".
Drive cycles but liquid section(s)
does not pump.
8" Drive Liquid Pumps • OM-LP-800F
7.2 Possible Cause
Air supply blocked or
inadequate.
Cycling valve spool binding.
Either pilot valve stem too short.
Exhaust or vent "iced up".
Mufflers plugged.
Broken pilot charge valve spring
(cycling valve end) causing it to
stick open. Then the pilot vent
valve cannot "dump" enough
pilot pressure so it remains held
open by the drive piston.
Defective o-ring on pilot charge
valve (cycling valve end)
causing high leakage into the
pilot system.
Insufficient drive air volume
causing cycling spool to hang up
in midstroke or drive-piston o-
ring to bypass air.
Shrinkage or damage to spool
seals and/or large drive piston
seal.
Check valve(s) not seating,
and/or leakage of plunger or
piston seal (paragraphs 5.6,
5.7).
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7.3 Remedy
Check air supply and regulator.
Clean spool by following cycling
valve disassembly instructions.
(Ref. paragraph 5.2)
Replace pilot valve with correct
part no.
Too much moisture in drive air.
Install better moisture reduction
system.
Remove, disassemble and clean
mufflers.
Replace spring.
Replace o-ring.
Increase drive air line size.
Inspect spool seals first.
(paragraph 5.2 ) If damaged,
replace and reset. If not
damaged, disassemble drive
and check large o-ring size per
Figure 8 and paragraph 5.5.5.
Per 6.5 - 6.5.2 test and inspect
check valves, plunger seal vent
ports and/or piston seals/pump
barrels for problem