Troubleshooting - Graco MERKUR 309463N Instructions-Parts List Manual

Troubleshooting

Troubleshooting
1. Relieve the pressure, page 12, before checking or
servicing the equipment.
Problem
Pump fails to operate.
Pump operates, but output is low on
both strokes.
Pump operates, but output is low on
downstroke.
Pump operates, but output is low on
upstroke.
Erratic or accelerated pump speed.
Fluid being pumped is visible in the
level display.
* To determine if the fluid hose or gun is obstructed, relieve the pressure. Disconnect the fluid hose and place a con-
tainer 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 hose or gun.
16
2. Check all possible problems and causes before dis-
Cause
Restricted line or inadequate air sup-
ply; closed or clogged valves.
Obstructed fluid hose or gun; fluid
hose ID is too small.
Fluid dried on the displacement rod.
Dirty, worn, or damaged air motor
parts.
Restricted line or inadequate air sup-
ply; closed or clogged valves.
Obstructed fluid hose or gun; fluid
hose ID is too small.
Worn packings in displacement
pump.
Held open or worn intake valve.
Held open or worn piston valve or
packings.
Exhausted fluid supply.
Held open or worn piston valve or
packings.
Held open or worn intake valve.
Worn throat packings.
assembling the pump.
Clear line or increase air supply.
Check that valves are open.
Open, clear*; use hose with larger ID.
Clean; always stop pump at the bot-
tom of its stroke. Keep wet-cup filled
with compatible fluid.
Clean or repair air motor. See man-
ual 309462.
Clear line or increase air supply.
Check that valves are open.
Open, clear*; use hose with larger ID.
Replace packings.
Clear valve, service; see manual
309462.
Clear valve; replace packings. See
manual 309462.
Refill and prime.
Clear valve; replace packings. See
manual 309462.
Clear valve, service; see manual
309462.
Replace throat packings; see manual
309462. Clean level display.
Solution
309463N