User's Manual

308357 11
Troubleshooting Chart
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 8.
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 supply;
closed or clogged valves.
Clear; increase air supply.
Check that valves are open.
Obstructed fluid hose or gun/valve;
fluid hose ID is too small.
Open, clear*; use hose with larger ID. Hose must
be rated for 510 bar (7400 psi).
Fluid dried on the displacement rod. Clean; always stop pump at bottom of stroke;
keep wet-cup 1/3 filled with compatible solvent.
Dirty, worn, or damaged motor parts. Clean or repair; see separate motor manual.
Pump operates, but
output low on both
strokes.
Restricted line or inadequate air supply;
closed or clogged valves.
Clear; increase air supply.
Check that valves are open.
Obstructed fluid hose or gun/valve;
fluid hose ID is too small.
Open, clear*; use hose with larger ID. Hose must
be rated for 51.0 MPa, 510 bar (7400 psi).
Worn packings in displacement pump. Replace packings.
Pump operates, but
output low on down-
stroke.
Held open or worn intake valve. Clear valve; service.
Pump operates, but
output low on upstroke.
Held open or worn piston valve or pack-
ings.
Clear valve; replace packings.
Erratic or accelerated
pump speed.
Exhausted fluid supply. Refill and prime.
Held open or worn piston valve or pack-
ings.
Clear valve; replace packings.
Held open or worn intake valve. Clear valve; 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. If the pump starts when the air is turned
on, the obstruction is in the fluid hose or gun.
NOTE: If you experience air motor icing, call your Graco distributor.