Troubleshooting
312226P
9
Displacement pump
operates, but output is
low on upstroke
Piston ball is not seating.
Service piston ball. Manual 309277.
Piston packings are worn or damaged.
Replace packings. Manual 309277.
Displacement pump
operates but output is low
on downstroke and/or on
both strokes.
Strainer (34e) is clogged.
Clean strainer.
O-ring in pump is worn or damaged.
Replace o-ring. Manual 309277.
Intake valve ball is packed with material or is not
seating properly.
Clean intake valve. Manual 309277.
Engine speed is too low.
Increase throttle setting. Manual 312190.
Suction tube air leak.
Tighten suction tube.
Pressure setting is too low.
Increase pressure. Manual 312190.
Fluid filter (11), tip filter or tip is clogged or dirty.
Clean filter. Manual 312190 or 311254.
Large pressure drop in hose with heavy materi-
als.
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).
Pump is difficult to prime. Air in pump or hose.
Check and tighten all fluid connections.
Reduce engine speed and cycle pump as slowly
as possible during priming.
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. Manual 309277.
Paint is too thick.
Thin the paint according to the supplier's recom-
mendations.
Engine speed is too high.
Decrease throttle setting before priming pump.
Manual 312190.
High engine speed at no
load.
Misadjusted throttle setting.
Reset throttle to 3700-3800 engine rpm at no
load.
Worn engine governor.
Replace or service engine governor.
Low stall or run pressure
shown on display.
New pump or new packings.
Pump break-in period takes up to 100 gallons of
material.
Faulty transducer.
Replace transducer.
Excessive paint leakage
into throat packing nut.
Throat packing nut is loose.
Remove throat packing nut spacer. Tighten throat
packing nut just enough to stop leakage.
Throat packings are worn or damaged.
Replace packings. Manual 309277.
Displacement rod is worn or damaged.
Replace rod. Manual 309277.
Fluid is spitting from gun. Air in pump or hose.
Check and tighten all fluid connections. Reprime
pump. Manual 312190.
Tip is partially clogged.
Clear tip. Manual 311254.
Fluid supply is low or empty.
Refill fluid supply. Prime pump. Manual 312190.
Check fluid supply often to prevent running pump
dry.
Problem
Cause
Solution