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Troubleshooting
311283H
7
Troubleshooting
PROBLEM
CAUSE
SOLUTION
Gas engine pulls hard (won't start)
Hydraulic pressure is too high
Turn hydraulic pressure knob coun
terclockwise to lowest setting
Gas engine does not start
Switch OFF, low oil, no gasoline
Consult engine manual, supplied
Gas engine doesn't work properly
Faulty engine
Consult engine manual, supplied
Gas engine operates, but displace
ment pump doesn't operate
Pump valve is OFF
Set pump valve ON
Pressure setting too low
Increase pressure
Displacement pump outlet filter (if
used) is dirty or clogged
Clean the filter
Tip or tip filter (if used) is clogged
Remove tip and/or filter and clean
Hydraulic fluid too low
Shut off sprayer. Add fluid*.
Belt worn, broken or off
Replace belt.
Hydraulic pump worn or damaged
Bring sprayer to Graco distributor for
repair
Dried paint seized paint pump rod
Service pump. See manual 311485
Hydraulic motor not shifting
Set pump valve OFF. Turn pressure
down. Turn engine OFF. Pry rod up
or down until hydraulic motor shifts.
Displacement pump operates, but
output is low on upstroke
Piston ball check not seating properly Service piston ball check. See man
ual 311485
Piston packings worn or damaged
Replace packings. See manual
311485
Displacement pump operates but
output is low on downstroke and/or
on both strokes
Piston packings worn or damaged
Tighten packing nut or replace pack
ings. See manual 311485
Intake valve ball check not seating
properly
Service intake valve ball check. See
manual 311485
Suction tube air leak
Paint leaks and runs over side of wet
cup
Loose wet-cup
Tighten wet-cup enough to stop leak
age
Throat packings worn or damaged
Replace packings. See manual
311485
Excessive leakage around hydraulic
motor piston rod wiper
Piston rod seal worn or damaged
Replace these parts.
Fluid delivery is low
Pressure setting too low
Increase pressure
Displacement pump outlet filter (if
used) is dirty or clogged
Clean filter
Intake line to pump inlet is not tight
Tighten
Hydraulic motor is worn or damaged Bring sprayer to Graco distributor for
repair
Large pressure drop in fluid hose
Use larger diameter or shorter hose