Graco PRO AA4500 Instructions-Parts List Manual page 37

SERVICE
Air Valve Repair
45
.
1.
Using a screw driver, remove the air valve cap (45).
See
Fig 20.
2.
Remove the O-ring (23) and spring (44).
ZJ
44
4 1 , 39\
CAUTION
ible with the fluid being used, such as xylol or min-
era1 spirits. Use of conductive solvents can cause
3. Loosen the air valve packing nut (40) one full turn,
then remove the air valve shaft (39).
CAUTION
When removing the air valve shaft (39) be careful
not to damage the seat area.
4. Check the O-rings (41,23) for damage and replace if
necessary. Apply petroleum jelly to the O-rings.
U-Cup
(42) llps
face Into
handle
5. Unscrew the packing nut (40) to check the u-cup
Fig
20
o w 1 4
(42).
Do not remove the u-cup unless it
is damaged.
lf the
u-cup
(42)
is removed, be sure to install the air
valve shaft (39) before installing the u-cup.
6. Install the air valve shaft, with the O-ring (41) into the
back of the gun handle (7).
7. If removed, install the u-cup with its lips facing into
the gun handle.
8. lighten the air valve packing nut (40).
9. Install the spring (44), O-ring (23) and air valve cap
bottoms.
(45). lighten the air valve packing nut (40) until it