Graco LineLazer IV 130 HS Manuel De L'opérateur page 39

Problem
Displacement pump
operates, but output is
low on upstroke
Displacement pump
operates but output is low
on downstroke and/or on
both strokes.
Pump is difficult to prime. Air in pump or hose.
High engine speed at no
load.
Low stall or run pressure
shown on display.
Excessive paint leakage
into throat packing nut.
Fluid is spitting from gun. Air in pump or hose.
313776D
Cause
Piston ball is not seating.
Piston packings are worn or damaged.
Strainer (34e) is clogged.
O-ring in pump is worn or damaged.
Intake valve ball is packed with material or is not
seating properly.
Engine speed is too low.
Suction tube air leak.
Pressure setting is too low.
Fluid filter (11), tip filter or tip is clogged or dirty.
Large pressure drop in hose with heavy materi-
als.
Intake valve is leaking.
Pump packings are worn.
Paint is too thick.
Engine speed is too high.
Misadjusted throttle setting.
Worn engine governor.
New pump or new packings.
Faulty transducer.
Throat packing nut is loose.
Throat packings are worn or damaged.
Displacement rod is worn or damaged.
Tip is partially clogged.
Fluid supply is low or empty.
Solution
Service piston ball. Manual 311845.
Replace packings. Manual 311845.
Clean strainer.
Replace o-ring. Manual 311845..
Clean intake valve. Manual 311845..
Increase throttle setting. Manual 313775.
Tighten suction tube.
Increase pressure. Manual 313775.
Clean filter. Manual 313775 or 311254.
Use larger diameter hose and/or reduce overall
length of hose. Use of more than 100 ft of 1/4 in.
hose significantly reduces performance of
sprayer. Use 3/8 in. hose for optimum perfor-
mance (50 ft minimum).
Check and tighten all fluid connections.
Reduce engine speed and cycle pump as slowly
as possible during priming.
Clean intake valve. Be sure ball seat is not nicked
or worn and that ball seats well. Reassemble
valve.
Replace pump packings. Manual 311845.
Thin the paint according to the supplier's recom-
mendations.
Decrease throttle setting before priming pump.
Manual 313775.
Reset throttle to 3700-3800 engine rpm at no
load.
Replace or service engine governor.
Pump break-in period takes up to 100 gallons of
material.
Replace transducer.
Remove throat packing nut spacer. Tighten throat
packing nut just enough to stop leakage.
Replace packings. Manual 311845.
Replace rod. Manual 311845.
Check and tighten all fluid connections. Reprime
pump. Manual 313775.
Clear tip. Manual 311254.
Refill fluid supply. Prime pump. Manual 313775.
Check fluid supply often to prevent running pump
dry.
Troubleshooting
9