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MAINTENANCE & TROUBLESHOOTING
GUN FAULTS
Condition
Will not spray
A
Gun ' spits' paint when triggering on
and off
A
Small air leak from air cap when
gun is not triggered
A
Gun ' spits' paint when triggering on
due to paint build-up inside air cap
A
between spraying operations
Slow fluid leak from fluid tip and
needle seat
B
Major fluid leak or fluid jetting from
fluid tip and needle seat
B
MAINTENANCE & TROUBLESHOOTING
Cause
No air pressure at gun
Internal mix or pressure feed air cap used
with suction feed
Fluid pressure too low with internal mix
cap and pressure tank
Fluid needle adjusting screw not open
enough
Fluid too heavy for suction feed
Incorrect needle fitted to gun
Excessive needle wear
Excessive fluid tip wear
Air valve contaminated and not correctly
seating
Air Valve seal damaged or missing
Fluid tip not fitted correctly in gun head
Fluid tip/needle leakage
Fluid Tip internal seat scored, damaged or
worn
Fluid needle external profile damaged or
worn
Contamination on needle or tip mating
surfaces preventing good seal
Incorrect fluid tip for fluid needle fitted to
gun
Sluggish needle
Tight packing nut
Contamination on needle or tip mating
surfaces preventing good seal
Incorrect fluid tip for fluid needle fitted to
gun
Fluid needle stuck or ' binding up'
PAGE 5
Correction
Check air supply and air lines
Change to proper suction feed air cap
Increase fluid pressure at tank
Open fluid needle adjusting screw
Thin material or change to pressure feed.
Check tip/needle selection chart and fit
correct item
Replace with new needle
Replace with new fluid tip
Remove valve and thorougly clean valve
shaft and seating surfaces
Replace
Tighten to correct torque
Check for damage or blockage
Replace
Replace
Thoroughly clean
Check tip/needle selection chart and fit
correct item
Lubricate packing
Adjust
Remove tip and needle and thoroughly
clean
Check tip/needle selection chart and fit
correct item
Remove and clean fluid needle shaft, or
lubricate needle packing or loosen needle
packing
PAGE 5
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