24 307-712
SERVICE
Piston Removal and Repair1. To disconnect the fluid hose (31) from the cover
plate (41), screw the nut (34) off the adapter (35).
See Fig 21.
2. Notethe position of the trigger adjusting nut (24) for
reinstallation,then screw it off the piston shaft.
3. Removethe screws (61) and lock washers (82) from
the cover plate (41). Remove the cover plate (41),
spring (38), and retainer cap (74).
4. Unscrew and remove the air valve guide (26) and
needle packing (27) from the gun body (1),
5. Pushon the end of the piston shaft, and remove the
piston assembly.
NOTE: DO NOT remove the uĆcup packing (37) from
the piston shaft except to replace it as removal
will damage this packing.
6. Clean and inspect parts for wear or damage. ReĆ
place parts as needed.
7. When reassembling the piston assembly,lubricate
theoĆrings (30 & 79) and the uĆcup packing (42) on
the piston with petroleum jelly.Pack the spring (38)
withpetroleum jelly. Apply Teflontape to the air valve
guide (26).
8. Install the new packing (27) and guide (26) in the
gun body (1); screw the guide in loosely.
NOTE: DO NOT fully tighten the guide (26) yet. The
guide must be loose to avoid damaging the
packing (27) when pushing the piston shaft
throughthe guide.
9. If replacing the uĆcup packing (37), slide it onto the
piston (42) so the lips of the packing will face toĆ
wards the front of the gun when the piston is inĆ
stalled. Then install the bunaĆn oĆring (30) and
Viton oĆring (79) on the piston.
10. Install the piston assembly into the gun body (1),
being careful not to damage the piston's lip seal.
11. Install the retainer cap (74) into the cover plate (41).
12. Install the cover plate (41), spring (38), and retainer
cap(74) with the screws (61) and lock washers (82).
13. Actuate the trigger and tighten the air valve guide
(26) with a wrench.
14. Screw the trigger adjusting nut (24) onto the piston
shaft to its previously noted position.
15. Connect the fluid hose (31) to the adapter (35).
Fig 21
KEY
1GunBody
24 TriggerAdjusting Nut
26 AirValve Guide
27 NeedlePacking
30 BunaĆnOĆRing
31 FluidTube
34 Nut
35 Adapter
37 UĆCupPacking
38 Spring
41 CoverPlate
42 Piston
61 Screws
74 RetainerCap
79 VitonOĆRing
82 LockWashers
26
Apply
Teflon
tape
24
31 34
27
41
35
82
61
30
79
37
38
74
Packwith
lubricant
42
1