Graco 223843, Instructions Manual

Page: 12 / 24

12 308106
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.
1. Relieve the pressure .
2. Check all possible causes and problems before
disassembling the pump.
PROBLEM CAUSE SOLUTION
Pump fails to operate Restricted line or inadequate air supply 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; stall-
ing
Service air motor (see 306982 or 307043).
Dried fluid seizure of displacement rod
(19)
Clean, check or replace throat packings (8, 13); al-
ways stop pump at bottom of stroke and keep wet-
cup filled with compatible solvent.
Pump operates, but
t t l b th
Restricted line or inadequate air supply Clear; increase air supply.
output low on both
strokes
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, valve, etc. Clear.*
Packing nut (4) too tight Loosen (see page 10).
Loose packing nut (4) or worn throat
packings (8, 13).
Tighten packing nut (see page 10);
replace throat packings
Pump operates, but
output low in 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 (8, 13).
Clear; service.
Erratic or accelerated
ti
Exhausted fluid supply Refill; purge all air from pump and fluid lines
operation
Held open or worn intake valve Clear; service.
Held open or worn fluid piston valve or
packings (8, 13).
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.