Graco B Series Instructions-Parts List Manual page 14

PROBLEM
Loss of air control or volume
at gun
Displacement pump output
low on upstroke low on upstroke
Displacement pump output
low on downstroke or both low on downstroke or both
strokes
Material leaks into wet-cup
Low fluid delivery
No fluid delivery
Spitting from gun
Heavy or poorly atomized
material when gun is first trig-
gered
Fluid from gun is not atom-
ized, or has insufficient
atomization atomization
Fluid from the gun is pulsing
14 308269
CAUSE
Air passages clogged with material
Piston ball (220) not seating
Piston packings worn or damaged
Siphon hose coupling gasket (1e)
worn or missing.
Pump cylinder o-ring (205) worn or
missing
Siphon hose strainer is clogged
Piston packings worn or damaged
Intake valve ball (216) not seating
properly
Clutch (9) worn or damaged
Loose wet-cup (202)
Throat packings worn or damaged
Displacement rod (201) worn or
damaged
Siphon hose strainer is clogged.
Engine RPM too low
Easy Spray Control not set to
SPRAY mode
Compressor is not on and/or air
hoses are not properly connected
Gun is not fully triggered
Fluid supply is low or empty
Fluid pressure was not allowed to
fully self relieve after releasing gun
trigger
Gun was not fully triggered immedi-
ately when squeezed, causing gun
air passages to clog with material.
Gun's Air Control Valve is turned
fully in
Insufficient compressor air
Gun nozzle too small for application
The fluid is too thin.
SOLUTION
After releasing the gun trigger, make sure
the system is fully depressurized before
triggering the gun again. This helps
prevent material backing into gun
passages.
Clean piston area. See page 20.
Replace packings. See page 20.
Replace or install gasket.
Check and replace.
Clean strainer.
Replace packings. See page 20.
Clean and service intake valve. See page
19.
Replace clutch. See page 26.
Tighten wet-cup just enough to stop
leakage.
Replace packings. See page 20.
Replace displacement rod. See page 20.
Clean or remove strainer.
Increase throttle setting. See Startup,
Steps 4, page 13.
Reset.
Check and correct.
Squeeze trigger firmly and completely.
Refill and prime the pump. See Startup,
page 13. Check fluid supply often to pre-
vent running the pump dry.
Wait a little longer between releasing gun
trigger and pulling it again.
Always squeeze the trigger fully to
prevent just the air from turning on, which
starts the pump and pressurizes the
hoses. Disassemble and clean gun.
Turn valve out for desired atomization.
Increase SCFM or compressor size.
Increase nozzle size.
Install the optional flow restrictor, 190109