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Troubleshooting
28 311796B
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 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
Elevation Refer to Engine Repair Kit.
4.0 hp - 288678 / 5.5 hp - 248943 /
6/5 hp - 248944 / 9.0 hp - 248945
Gas engine operates, but displacement pump
doesn't operate
Hydraulic pump valve is OFF Set hydraulic pump valve ON
Pressure setting too low Increase pressure, page 21
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*. See page 17
Belt worn or broken or off Replace. See manual 311797
Hydraulic pump worn or damaged Bring sprayer to Graco distributor for repair
Dried paint seized paint pump rod Service pump. See manual 311845
Hydraulic motor not shifting Set pump valve OFF. Turn pressure down. Turn
engine OFF. Pry rod up or down until hydraulic
motor shifts. Manual 311797
Displacement pump operates, but output is low
on upstroke
Piston ball check not seating properly Service piston ball check. See manual 311845
Piston packings worn or damaged Replace packings. See manual 311845
Displacement pump operates but output is low
on downstroke and/or on both strokes
Piston packings worn or damaged Tighten packing nut or replace packings.
See manual 311845
Intake valve ball check not seating properly Service intake valve ball check.
See manual 311845
Suction tube air leak
Paint leaks and runs over side of wetcup Loosen wet-cup Tighten wet-cup enough to stop leakage
Throat packings worn or damaged Replace packings. See manual 311845
Excessive leakage around hydraulic motor
piston rod wiper
Piston rod seal worn or damaged Replace these parts. See manual 311797
Fluid delivery is low Pressure setting too low Increase pressure, page 21
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
The sprayer overheats Paint builup on hydraulic components Clean
Oil level is low Fill with oil. See page 17
Spitting from gun Air in fluid pump or hose Check for loose connections on siphon
assembly, tighten, then reprime pump
Loose intake suction Tighten
Fluid supply is low or empty Refill supply container
Excessive hydraulic pump noise Low hydraulic fluid level Turn sprayer OFF. Add fluid*. See page 17
Electric motor does not operate Power switch is not ON Turn power switch to ON
Tripped circuit breaker Check circuit breaker at power source.
Reset motor switch
*Check hydraulic fluid level often. Do not allow it to become too low. Use only Graco approved hydraulic fluid, page 17.