Piston Repair - Graco PRO Auto Xs Series Instructions-Parts List Manual

Repair

Piston Repair

1. Prepare the gun for service, page 32.
2. Remove the air cap, page 34. Remove the gun
shroud (2).
3. Remove the jam nut (28), actuator arm (29), and
adjustment nut (30). See F
The fluid nozzle (4) must be in place when removing or
installing the jam nut and actuator arm.
28
Fig. 25. Actuator Arm
4. Push on the piston rod (34b) to push the piston out
the back of the gun.
5. Inspect the o-rings (34e, 34f, 34g) and u-cup pack-
ing (34d) for damage. See Table 5 and F
6. Lubricate the o-rings (34e, 34f, 34g) and u-cup
packing (34d) with non-silicone grease, Part No.
111265. Do not over-lubricate.
7. Align the two stems (34c) with the holes in the gun
body and press the piston assembly into the back of
the gun until it bottoms.
8. Install and adjust the actuator arm, page 39.
38
25.
IGURE
TI1709A
29 30 34b
IGURE
Table 5: Piston O-Rings
Description
Shaft O-Ring
(34g)
Front O-Ring
(34e)
Back O-Ring
(34f)
U-Cup (34d)
34f
34e
26.
Fan Air Side
Atomizing Air Side
Fig. 26. Piston O-Rings
Function
Seals cylinder air along the piston rod
(34b). Replace if air leaks along rod.
Air shutoff seal. Replace if air leaks from
air cap when gun is de-triggered.
Separates cylinder air from fan and
atomizing air.
Replace if air leaks from small vent hole
at back of manifold when gun is trig-
gered.
34a
34d
34c
34b
34d
34g
34f
34e
34g
TI1575A
TI1576A
309297K