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Troubleshooting
310778N 7
Troubleshooting
Problem Cause Solution
Gas engine pulls hard (won't start) Hydraulic pressure is too high Turn hydraulic pressure knob counter-
clockwise to lowest setting
Gas engine will not start Switch OFF, low oil, no gasoline Consult engine manual, supplied
Gas engine doesn't work properly
Elevation
Consult engine manual, supplied.
Refer to 6.5 HP Engine Repair Kit 246311.
Gas engine operates, but displace-
ment pump doesn't operate
Pump valve is OFF
Pressure setting too low
Displacement pump outlet filter (if
used) is dirty or clogged
Tip or tip filter (if used) is clogged
Hydraulic fluid too low
Belt worn or broken
Hydraulic pump worn or damaged
Dried paint seized paint pump rod
Hydraulic motor not shifting
Set pump valve ON
Increase pressure. See manual 310765
Clean filter
Remove tip and/or filter and clean
Shut off sprayer. Add fluid*. See page 6.
Replace
Bring sprayer to Graco distributor for
repair
Service pump. See manual 309277.
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 prop-
erly.
Piston packings worn or damaged.
Service piston ball check. See manual
309277.
Replace packings. See manual 309277.
Displacement pump operates but
output is low on downstroke and/or
on both strokes
Piston packings worn or damaged.
Intake valve ball check not seating
properly.
Suction tube air leak
Tighten packing nut or replace pack-
ings. See manual 309277.
Service intake valve ball check. See
manual 309277.
Tighten suction tube
Paint leaks and runs over side of wet-cup
Loose wet-cup
Throat packings worn or damaged
Tighten packing nut enough to stop leakage
Replace packings. See manual 309277
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
Displacement pump outlet filter (if used)
is dirty or clogged
Intake line to pump inlet is not tight
Hydraulic motor is worn or damaged
Large pressure drop in fluid hose
Increase pressure. See manual 310765.
Clean filter
Tighten
Bring sprayer to Graco distributor for repair
Use larger diameter or shorter hose
The sprayer overheats
Paint buildup on hydraulic components
Oil level is low
Clean
Fill with oil. See page 6.
Spitting from gun Air in fluid pump or hose
Loose intake suction
Fluid supply is low or empty
Check for loose connections on siphon
assembly, tighten, then reprime pump
Tighten
Refill supply container
Excessive hydraulic pump noise Low hydraulic fluid level
Shut off sprayer. Add fluid*. See page 6.
*Check hydraulic fluid level often. Do not allow it to become too low. Use only Graco approved hydraulic fluid, page 6.