Graco Check-Mate 450, Manual

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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 problems and causes before
disassembling the pump.
PROBLEM CAUSE SOLUTION
Pump fails to operate. Restricted line or inadequate air supply;
closed or clogged valves. Clear; increase the air supply.
Check that all valves are open.
Obstructed fluid hose or gun/valve;
fluid hose ID is too small. Open, clear*; use a hose with a larger ID.
Fluid dried on the displacement rod. Clean; always stop the pump at the bottom of its
stroke; keep the wet-cup 1/3 filled with a compat-
ible solvent.
Dirty, worn, or damaged motor parts. Clean or repair; see the separate motor manual.
Pump operates, but
output is low on both
strokes. Restricted line or inadequate air supply;
closed or clogged valves. Clear; increase the air supply.
Check that all valves are open.
Obstructed fluid hose or gun/valve;
fluid hose ID is too small. Open, clear*; use a hose with a larger ID.
Bleeder valve is open. Close the valve.
Air is leaking into the supply container. Check the ram plate seal.
Fluid is too heavy for pump priming. Use the bleeder valve (see page 10); use a ram.
Held open or worn intake valve or seals. Clear the valve; replace the seals.
Worn packings in the displacement
pump. Replace the packings.
Pump operates, but
output is low on down-
stroke. Fluid too heavy for pump priming. Use the bleeder valve (see page 10); use a ram.
Held open or worn intake valve or seals. Clear the valve; replace the seals.
Pump operates, but
output is low on up-
stroke. Held open or worn piston valve or seals. Clear the valve; replace the seals.
THE TROUBLESHOOTING CHART IS CONTINUED ON PAGE 13.
* To determine if the fluid hose or gun is obstructed, follow the Pressure Relief Procedure on page 9. 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.