Graco PRO AA4500 Instructions-Parts List Manual page 36

Service
Air Control Valve
Repair
NOTE: The air control valve (43) can be replaced as
an assembly or as individual parts.
To disassemble the air control valve,
1.
Remove the retaining ring (43h). See Fig.
19.
2.
Slide the W HI-LO lever (439) up and remove the
air control valve assembly (43) with an adjustable
wrench.
3.
Remove the retaining ring (43b).
4. Rotate the air adjusting screw (43c) counterclock-
wise until it is disengaged from the valve housing
threads (43d). Then pull the adjusting screw out
of the valve housing.
The W HI-LO lever (439) and the wave spring
(439 can be removed if necessary.
5.
Clean all the parts and inspect them for wear or
damage, :'
6.
If replacing the seal (43a), unscrew it clockwise
and remove it from the adjusting screw (43c). Ap-
threads on the end of the adjusting screw (43c)
ply medium grade thread sealant to the small
and install a new seal (43a) (left hand thread).
7. Reassembling the fan air valve (43). Lubricate the
O-rings (43e) and the adjusting screw threads
(43c) with petroleum jelly.
8. Apply low strength (purple) Loctite or equivalent
thread sealant to the threads of the valve housing
(43d) and Install the air control valve assembly
into the gun handle.
To start the valve housing (43d) threads into the
handle, turn the adjusting screw (43c). Once the
threads are started, turn the adjusting screw (43C)
fully counterclockwise.
Then tighten the valve housing into the gun han-
dle, torquing it to
10
to
12
in-lb
(1.1
to
1.4
N-m).
9. Install the retaining ring (43h) back into the
groove in the valve housing (43d).
43e 43f 43h 43c
Toraue to
1
Fig. 19
0 1 w
36 308-294