Gun Operation Troubleshooting - Graco PRO AA5500sc unicarb Instruction Manual

Gun Operation Troubleshooting

PROBLEM
Leakage from fluid needle area
Air leakage from front of gun
Fluid leakage from front of gun
"Orange Peel" finish
Excessive spray fog
No fluid sprays from gun
Equipment covered with fluid
Paint build-up on air cap
Fluid doesn't shut off properly
Air leakage from manifold
* Use the least fluid pressure needed for good results.
Troubleshooting
CAUSE
Fluid needle packings loose
Fluid needle packing damaged
Piston air valve not seating properly
Fluid needle worn
Fluid seat loose or worn
Spray tip loose
Tip seal damaged
2
CO percentage is too low
Fluid pressure too low
Spray tip or pre-orifice too large
Fluid poorly mixed or filtered
Improper thinner being used
Fluid thinned too much
Fluid supply low
Cylinder air pressure too low
Spray tip or pre-orifice is dirty or clogged
Spray tip damaged
Actuator arm not adjusted properly
Piston sticking
Fluid needle damaged
Booth exhaust air flow too low or not
directed properly
Improper distance between gun and
workpiece
Gun shroud loose or o-ring (9) missing
2
CO percentage too high
Air cap dirty
Seat housing over-tightened
Fluid leakage buildup on fluid needle
Fluid packings too tight
Piston sticking
Manifold not tight
Worn or missing o-rings
SOLUTION
Tighten packing nut; See page 39
Replace fluid needle; See page 39
Clean, Service; See page 36
Replace fluid needle; See page 39
Tighten or replace fluid seat
Tighten retaining nut
Replace tip seal; See page 33
2
Increase CO percentage
Increase fluid pressure with gun fluid regulator*
Use a smaller size spray tip or pre-orifice;
See page 51
Remix or refilter fluid
Use proper thinner
Properly thin fluid
Check; Add fluid if necessary
Increase cylinder air pressure; 65 psi (4.5
bar, 0.45 MPa) minimum required
Clean spray tip and pre-orifice; See page 23
Check; Replace spray tip; See page 33
Adjust the actuator arm; See page 36
Service piston o-rings; See page 36
Replace fluid needle; See page 39
Check for proper CFM; Check baffles and
direction of air flow
Adjust spraying distance to 8 to 12 inches
(203 to 305 mm)
Tighten retaining nut (1); Check o-ring (9);
See page 44
2
Reduce CO percentage
Clean air cap; See page 23
Replace seat housing; See page 33
Replace fluid needle; See page 39
Adjust fluid packings; See page 39
Service piston o-rings; See page 36
Tighten manifold screws; See page 43
Inspect or replace o-rings (items 5 and 118);
see pages 44 and 46
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