Air Valve Repair - Graco PRO AA4500 Instructions-Parts List Manual

Service
Air Valve Repair
1. Using a screw driver, remove the air valve cap
(45). See Fig. 20.
r c A U T l o N
1
2.
Remove the O-ring (23) and spring
(44).
Clean all parts in non-conductive solvent cornpat-
ible with the fluid being used, such as xylol or min-
the gun to malfunction.
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.
5. Unscrew the packing nut (40) to check the u-cup
aged.
M
the u-cup (42) is removed, be sure to
(42).
Do not remove the u-cup unless
it
is dam-
install the air valve shaft (39) before installing the
u-cup.
7. If removed, install the u-cup with its lips facing
into the gun handle.
8.
Tighten the air valve packing nut (40).
9, Install the spring
(44),
O-ring (23) and air valve
cap (45). Tighten the air valve packing nut (40)
until it bottoms.
40,42
U-Cu (42)
UPS
face
Ito
handle
6.
Install the air valve shaft, with the O-ring (41) into
the back of the gun handle
(7).
Fig. 20
02014A
308-294 37