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Troubleshooting
311283D 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