Troubleshooting - Graco Dura-Flo 7847 Instructions Manual

Troubleshooting

Troubleshooting
Problem
Pump fails to operate.
Pump operates, but output low on both
strokes.
Pump operates, but output low on down-
stroke.
Pump operates, but output low on
upstroke.
Erratic or accelerated pump speed.
* To determine if the fluid hose or gun is obstructed, relieve the pressure, page 13. Disconnect the fluid hose and
place a container at the pump fluid outlet to catch any fluid. Turn on the air/hydraulic power just enough to start the
pump. If the pump starts, the obstruction is in the fluid hose or gun.
16
1. Relieve the pressure, page 13.
2. Check all possible causes and problems before dis-
Cause
Restricted line or inadequate air/hydrau-
lic supply; closed or clogged valves.
Obstructed fluid hose or gun/valve; fluid
hose ID is too small.
Fluid dried on displacement rod.
Dirty, worn, or damaged motor parts.
Restricted line or inadequate air/hydrau-
lic supply; closed or clogged valves.
Obstructed fluid hose or gun/valve; fluid
hose ID is too small.
Bleeder valve open.
Fluid too heavy for pump priming.
Worn packings in lower.
Held open or worn intake valve.
Fluid too heavy for pump priming.
Held open or worn piston valve or pack-
ings.
Exhausted fluid supply.
Fluid too heavy for pump priming.
Held open or worn piston valve or pack-
ings.
Held open or worn intake valve.
assembling the pump.
Clear; increase air/hydraulic supply.
Check that valves are open.
Open, clear*; use hose with larger ID
Clean; always stop pump at bottom of
stroke; keep wet-cup 1/3 filled with com-
patible solvent.
Clean or repair; see separate motor
manual.
Clear; increase air/hydraulic supply.
Check that valves are open.
Open, clear*; use hose with larger ID
Close.
Use ram.
Replace packings.
Clear valve; service.
Use ram.
Clear valve; replace packings.
Refill and prime.
Use ram.
Clear valve; replace packings.
Clear valve; service.
Solution
311828F