Graco GMAX 3400 Operation page 30

Troubleshooting
Problem
Excessive paint leakage into throat
packing nut
Fluid is spitting from gun
Pump is difficult to prime
Clutch squeaks each time clutch
engages
High engine speed at no load
Gallon counter not working
No display, sprayer operates
30
Cause
Throat packing nut is loose.
Throat packings are worn or damaged.
Displacement rod is worn or damaged.
Air in pump or hose.
Tip is partially clogged.
Fluid supply is low or empty.
Air in pump or hose.
Intake valve is leaking.
Pump packings are worn.
Engine speed is too high.
Clutch surfaces are not matched to
each other when new and may cause
noise.
Misadjusted throttle setting.
Worn engine governor.
Bad sensor, broken or disconnected
wire. Displaced or missing magnet.
Display damaged or has bad
connection.
Solution
Remove throat packing nut spacer. Tighten
throat packing nut just enough to stop
leakage.
Replace packings (see pump manual).
Replace rod (see pump manual).
Check and tighten all fluid connections.
Reprime pump (see operation manual).
Clear tip (see gun manual).
Refill fluid supply. Prime pump (see operation
manual). Check fluid supply often to prevent
running pump dry.
Check and tighten intake tube 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 (see pump manual).
Decrease throttle setting before priming pump
(see operation manual).
Clutch surfaces need to wear into each other.
Noise will dissipate after a day of run time.
Reset throttle to 3300 engine rpm at no load.
Replace or service engine governor.
Check connections. Replace sensor or wire.
Reposition or replace magnet.
Check connections. Replace display.
3A6400A