Troubleshooting - Graco D Series Instructions And Parts List

Troubleshooting

Problem
Pump fails to operate.
Continuous air exhaust
Erratic pump operation
Pump operates, but output low on
up stroke
Pump operates, but output low on
down stroke
Pump operates, but output low on
both strokes
Fluid is coming out of the muffler
*Follow the Pressure Relief Procedure, page 8, then disconnect the fluid line. If the pump starts when the air is
turned on again, there is a clog in the line, hose, valve, etc.
308608L
1. Follow Pressure Relief Procedure, page 8, before
checking or repairing the pump.
2. Check all possible problems and causes before
disassembling pump.
Cause
Inadequate air supply pressure or
restricted air lines
Closed or clogged dispensing valve
Clogged fluid lines, hoses, valves,
etc.
Damaged air motor
Exhausted fluid supply
Worn or damaged air motor gasket,
packing, seal, etc.
Exhausted fluid supply
Held open or worn intake valve or
piston packings
Held open or worn piston packings
Held open or worn intake valve
Inadequate air supply pressure or
restricted air lines
Closed or clogged valves
Worn or damaged throat seal
Troubleshooting
Solution
Increase air supply; clear
Open; clear
Clear*
Service air motor
Refill and re-prime or flush
Service air motor
Refill and re-prime or flush
Clear; service
Clear; service
Clear; service
Increase air supply; clear
Open; clear
Repair
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