Graco Inc. 247550 Benutzerhandbuch

1.

Relieve the pressure, page 9. 

2.

Check all possible causes and problems before dis-
assembling the pump.

To determine if the fluid hose or gun is obstructed, relieve the pressure, page 9. Disconnect the fluid hose and 
place a container at the pump fluid outlet to catch any fluid. Turn on the air power just enough to start the pump. If 
the pump starts, the obstruction is in the fluid hose or gun.

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.

Fluid dried on displacement rod.

Clean; always stop pump at bottom of 
stroke; keep wet-cup 1/3 filled with com-
patible solvent.

Dirty, worn, or damaged motor parts.

Clean or repair. See manual 311238.

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.

Bleeder valve open.

Close.

Worn packings in displacement pump.

Replace packings. See displacement 
pump manual 311825 or 312745.

Pump operates, but output low on down-
stroke.

Held open or worn intake valve.

Clear valve; service. See displacement 
pump manual 311825 or 312745.

Pump operates, but output low on 
upstroke.

Held open or worn piston valve or pack-
ings.

Clear valve; replace packings. See dis-
placement pump manual 311825 or 
312745.

Erratic or accelerated pump speed.

Exhausted fluid supply.

Refill and prime.

Held open or worn piston valve or pack-
ings.

Clear valve; replace packings. See dis-
placement pump manual 311825 or 
312745.

Held open or worn intake valve.

Clear valve; service. See displacement 
pump manual 311825 or 312745.