Troubleshooting
44
3A2593C Repair
Engine operates, but
displacement pump does
not operate
Main power switch is OFF. *
Turn main power switch ON.
Engine clutch switch is OFF.**
Turn engine clutch switch ON.
Pump valve is OFF.
Turn pump valve ON.
Pressure setting is too low.
Turn pressure adjusting knob clockwise to increase
pressure. See operation manual.
Prime/drain valve is closed and system
is pressurized.
Open prime/drain valve.
Hydraulic fluid too low.
Shut off sprayer. Add fluid*.
Oil reservoir belt is worn, broken, or off
the pulley.
Replace oil reservoir belt. See page 12.
Tip is clogged.
Reverse tip to clean. See manual 311254.
Displacement pump piston rod is stuck due to
dried paint.
Repair pump. See manual 309277.
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 is not seating.
Service piston ball. See manual 309277.
Piston packings are worn or damaged.
Replace packings. See manual 309277.
Displacement pump operates but output
is low on downstroke and/or on both
sides
Suction tube strainer is clogged.
Clean strainer.
Suction tube air leak.
Tighten suction tube.
Pressure setting is too low.
Increase pressure. See operation manual.
Fluid filter or tip is clogged or dirty.
Clean filter and tip. See operation manual or gun
manual 311254.
Engine speed is too low.
Increase throttle setting. See operation manual.
Intake valve ball is packed with material or is
not seating properly.
Clean intake valve. See manual 309277.
Pump packings are worn or damaged.
Replace pump packings. See manual 309277.
Large pressure drop in hose with heavy
materials.
Use larger diameter hose and/or reduce overall length
of hose. Use of more than 100 ft x 1/4 in. hose signifi-
cantly reduces performance of sprayer. Use 3/8 in.
hose for optimum performance.
Oil reservoir hydraulic filter is dirty or clogged.
Change hydraulic filter and hydraulic oil.
Intake line to pump inlet is not tight.
Tighten intake line to pump inlet.
Hydraulic motor is worn or damaged.
Bring sprayer to Graco distributor for repair.
Pump is difficult to prime
Suction tube strainer is clogged.
Clean strainer
Suction tube air leak.
Tighten suction tube
Drain line to paint hopper is clogged.
Clean drain line
Intake valve is leaking.
Clean intake valve. Be sure ball seat is not nicked or
worn and that ball seats well. Reassemble valve.
Pump packings are worn.
Replace pump packings. See manual 309277.
Paint is too thick.
Thin the paint according to supplier recommendations.
Engine speed is too high.
Decrease throttle setting before priming pump. See
operation manual.
Problem
Cause
Solution
Summary of Contents for LineLazer IV 250SPS
Page 53: ...Notes 3A2593C Repair 53 Notes ...
