Graco PRO AA4500 Instructions-Parts List Manual page 36

Air
Control
Valve Repair
NOTE The air control valve (43) can be replaced as an
To disassemble the air control valve,
1. Remove the retaining ring (43h). See Fig 19.
2. Slide the KV HI-LO lever (439) up and remove the air
control valve assembly (43) with
an
adjustable
wrench.
assembly or as individual parts.
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 KV 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). Apply
on the end of the adjusting screw (43c) and install a
medium grade thread sealant to the small threads
new seal (43a) (left hand thread).
7. Reassembling the fan air valve (43). Lubricate the
O-rings (43e) and the adjusting screw threads (4%)
with petroleum jelly.
8. Apply low strength (purplej 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 han-
dle, turn the adjusting screw (43c). Once the
threads are started, turn the adjusting screw (43c)
fully counterclockwise.
torquing it to 10 to 12 in-lb (1.1 to 1.4 Nom).
Then tighten the valve housing into the gun handle,
9. Install the retaining ring (43h) back into the groove
in the valve housing (43d).
43e 431 43h 43c
mBs
10-12 In-lb
(1.1-1.4N-m)
43
Fig 19
01054
36 308-294