Piston Repair - Graco 333013B Instructions - Parts Manual

F . 31 Fluid Needle Removal
IG
F . 32 Fluid Needle Replacement
IG

Piston Repair

1. Prepare the gun for service, page 38.
2. Remove the air cap, page 39. Remove the gun
shroud (26).
3. Remove the jam nut (16a), actuator arm (15), and
adjustment nut (16b). See F
4. Remove piston cap (13) and spring (12) from the
rear of the gun.
5. Push on the piston rod (11) to push the piston out
the back of the gun.
6. Inspect the o-rings (11d, 11e, 11f, 11g) for damage.
See Table 3 and F
IGURE
7. Lubricate the o-rings (11d, 11e, 11f, 11g) with
non-silicone grease, Part No. 111265. Do not
over-lubricate.
8. Align the two stems (11c) with the holes in the gun
body and press the piston assembly into the back of
the gun until it bottoms. Install piston cap (13) and
spring (12).
9. Install and adjust the actuator arm, page 42.
333013B
N
48
34.
IGURE
33.
11c
11f
11e
11g
11f
11e
Fan Air Side
Atomizing Air Side
F . 33 . Piston O-Rings
IG
Table 3. Piston O-Rings
Description
Shaft O-Ring Seals cylinder air along the piston rod
(11g) (34b). Replace if air leaks along rod.
Front O-Ring Air shutoff seal. Replace if air leaks from
(11e) air cap when gun is de-triggered.
Back O-Ring Separates cylinder air from fan and atom-
(11f) izing air.
Piston O-Ring Replace if air leaks from small vent hole
(11d) at back of manifold when gun is triggered.
O-rings included in air seal repair kit 24W390
11a
11d
11b
11d
11g
Function
Repair
41