Troubleshooting - Graco 310778N Repair Manual

Problem
Gas engine pulls hard (won't start)
Gas engine will not start
Gas engine doesn't work properly
Gas engine operates, but displace-
ment pump doesn't operate
Displacement pump operates, but
output is low on upstroke
Displacement pump operates but
output is low on downstroke and/or
on both strokes
Paint leaks and runs over side of wet-cup Loose wet-cup
Excessive leakage around hydraulic
motor piston rod wiper
Fluid delivery is low
The sprayer overheats
Spitting from gun
Excessive hydraulic pump noise
*Check hydraulic fluid level often. Do not allow it to become too low. Use only Graco approved hydraulic fluid, page 6.
310778N

Troubleshooting

Cause
Hydraulic pressure is too high
Switch OFF, low oil, no gasoline
Elevation
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
Piston ball check not seating prop-
erly.
Piston packings worn or damaged.
Piston packings worn or damaged.
Intake valve ball check not seating
properly.
Suction tube air leak
Throat packings worn or damaged
Piston rod seal worn or damaged
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
Paint buildup on hydraulic components
Oil level is low
Air in fluid pump or hose
Loose intake suction
Fluid supply is low or empty
Low hydraulic fluid level
Solution
Turn hydraulic pressure knob counter-
clockwise to lowest setting
Consult engine manual, supplied
Consult engine manual, supplied.
Refer to 6.5 HP Engine Repair Kit 246311.
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
Service piston ball check. See manual
309277.
Replace packings. See manual 309277.
Tighten packing nut or replace pack-
ings. See manual 309277.
Service intake valve ball check. See
manual 309277.
Tighten suction tube
Tighten packing nut enough to stop leakage
Replace packings. See manual 309277
Replace these parts
Increase pressure. See manual 310765.
Clean filter
Tighten
Bring sprayer to Graco distributor for repair
Use larger diameter or shorter hose
Clean
Fill with oil. See page 6.
Check for loose connections on siphon
assembly, tighten, then reprime pump
Tighten
Refill supply container
Shut off sprayer. Add fluid*. See page 6.
Troubleshooting
7