Replace Trigger Valve O-Rings - Graco GX-8 Operation, Parts, Service, Repair

Replace Trigger Valve
O-Rings
1. Clean gun (see Clean Spray Gun Proce-
dure, page 15).
2. Perform Pressure Relief Procedure, page
14.
3. Disconnect air supply from gun.
Refer to Parts, page 24.
Spring
Seat
Valve
Liner
O-rings
Valve
Spring
Valve
Spool
Valve Retainer Nut
F . 18: Replace Trigger Valve O-Ring
IG
4. Use 6 in. adjustable wrench and 6 in. pliers
to remove screw and locknut that hold trig-
ger lever in place. Remove trigger lever.
5. Use 3/8 in. wrench to loosen and remove
valve retainer nut.
6. Remove valve spool and spring:
a. Grab end of spool and pull out. Spring
will come out with spool. Do not lose
spring--it belongs in hole at end of
spool.
b. Remove old rings.
22
1/16 in. Pipe
Plug
1/8 in.
Pipe Plug
Optional 1/8 in.
Pipe Nipple
Trigger Mounting
Screw
Trigger Lever
c. Apply thin coat of Lubriplate grease to
new rings and reinstall.
Follow steps 6-14 to replace rings on
valve liner. If rings do not need to be
replaced, proceed to step 15.
7. Use 3/16 in. hex key to remove 1/8 in. rear
internal plug. This plug seals another air-
flow path in gun handle.
For guns configured with air inlet at rear
of gun handle, pipe nipple replaces pipe
plug. Remove pipe nipple.
8. Use 5/32 in. hex key to remove rear internal
pipe plug (under pipe plug).
9. Use pin punch and hammer to gently tap
spring seat until it and valve liner push out
opposite end of hole.
10. Remove rings on liner. Apply thin coat of
Lubriplate grease to new rings and install.
11. Clean valve hole. Remove any dirt and
debris. Apply thin coat of Lubriplate grease
to inside of valve hole.
12. Slide spring seat into gun handle air valve
hole, tapered end first, until it bottoms out.
13. Push valve liner in as far as it will go. Install
valve retainer nut, it will align valve liner
and spool to their proper depth.
14. Use 5/32 in. hex key to screw 1/16 in. pipe
plug back into place. Apply think coat of
pipe thread sealant to threads prior to
insertion to help prevent air leaks.
15. Apply small amount of pipe thread sealant
to 1/8 in. plug threads. Screw pipe plug in
place.
16. Insert valve spool into valve liner with valve
spool spring still in place. Screw in valve
retainer nut; tighten until snug.
Repair
311338B