Graco 3400 - Manual (Page 7)

Troubleshooting
310813 Rev C 7
Problem Cause Solution
Pump output is low Strainer (16) is clogged Clean strainer.
Piston ball (206) is not seating Service piston ball. Manual 309250.
Piston packings are worn or damaged Replace packings. Manual 309250.
O-ring (227) in pump is worn or damaged Replace o-ring. Manual 309250.
Intake valve ball is not seating properly Clean intake valve. Manual 309250.
Intake valve ball is packed with material Clean intake valve. Manual 309250.
Engine speed is too low Increase throttle setting. Manual 310802.
Clutch is worn or damaged Adjust or replace clutch. Page 9.
Pressure setting is too low Increase pressure. Manual 310802.
Fluid filter (29), tip filter or tip is
clogged or dirty Clean filter. Manual 310802 or 309639.
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 of 1/4 in. hose signifi-
cantly reduces performance of sprayer.
Use 3/8 in. hose for optimum perfor-
mance (50 ft minimum).
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 309250.
Displacement rod is worn or damaged Replace rod. Manual 309250.
Fluid is spitting from gun Air in pump or hose Check and tighten all fluid connections.
Prime pump. Manual 310802.
Tip is partially clogged Clear tip. Manual 309639.
Fluid supply is low or empty Refill fluid supply. Prime pump. Manual
310802. Check fluid supply often to
prevent running pump dry.
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 309250.
Paint is too thick Thin the paint according to the sup-
plier's recommendations
Engine speed is too high Decrease throttle setting before prim-
ing pump. Manual 310802.
Clutch squeaks each time clutch
engages Clutch surfaces are not matched to each
other when new and may cause noise Clutch surfaces need to wear into each
other. Noise will dissipate after a day of
run time.
High engine speed at no load Misadjusted throttle setting Reset throttle to 3300 engine rpm at no
load
Worn engine governor Replace or service engine governor