13308118
Troubleshooting
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 9.
Before servicing this equipment always make sure to
relieve the pressure.
Check all possible problems and solutions before
disassembling the pump.
Problem
Cause Solution
Pump fails to operate
Restricted line or inadequate air sup-
ply
Clear; Increase air supply.
Insufficient air pressure; closed or
clogged air valves, etc.
Open, clean.
Exhausted fluid supply Refill; purge all air from pump and
fluid lines.
Damaged air valving mechanism;
stalling
Service air motor (see manual
306982 or 307043).
Dried fluid seizure of displacement
rod (1)
Clean, check or replace throat pack-
ings (3, 25); always stop the pump at
the bottom of its stroke and keep the
wet-cup filled with compatible solvent.
Pump operates, but output low on
both strokes
Restricted line or inadequate air sup-
ply
Clear; increase air supply.
Insufficient air pressure; closed or
clogged air valves, etc.
Open, clean.
Exhausted fluid supply Refill; purge all air from pump and
fluid lines.
Clogged fluid line, valves, etc. Clear*.
Packing nut (14) too tight Loosen (see page 10).
Loose packing nut (14) or worn throat
packings (3, 25)
Tighten packing nut (see page 10);
replace throat packings.
Pump operates, but output low on
down stroke
Held open or worn intake valve. Clear; service.
Pump operates, but output low on
up stroke
Held open or worn fluid piston valve
or packings (29, 30)
Clear; service.
Erratic or accelerated operation
Exhausted fluid supply Refill; purge all air from the pump and
fluid lines.
Help open or worn intake valve. Clear; service.
Help open or worn fluid piston valve
or packings (29, 30)
Clear; service.
* To determine if the fluid hose or gun is obstructed, relieve the pressure. Disconnect the fluid hose and place a container at the
pump fluid outlet to catch any fluid. Turn on the air just enough to start the pump (about 20–40 psi [140–280 kPa, 1.4–2.8 bar]). If
the pump starts when the air is turned on, the obstruction is in the fluid hose or gun.