Remove Centerline Components; Install Centerline Components - Graco GX-8 Operation, Parts, Service, Repair

Remove Centerline
Components
Refer to page 8 for diagrams of centerline components
for all gun models.
1. Flush gun (see Clean Spray Gun Procedure, page
19).
2. Remove air cap (loosen by hand).
3. Use 10 in. adjustable wrench to remove PCD.
4. Connect air supply to gun.
5. Lift PCD off nose of gun block and remove.
NOTE: To remove PCD that is stuck, set safety stop to
OPEN, depress and release gun trigger to unseat it.
CLOSE safety stop.
6. Remove mixing module retainer.
7.
OPEN safety stop. Depress and release gun trigger
to unseat it. Remove mixing module off end of valv-
ing rod. CLOSE safety stop.
Do not use sharp objects or metal tools to remove
mixing module.
8. Disconnect air supply from gun.
9. Use 5/16 in. wrench to loosen packing nut 3 or 4
turns.
10. Remove gun block:
a. Use 5/16 in. nut driver to remove gun block
retaining screw.
b. Slide gun block away from valving rod and air
cylinder. If dried chemical is built up on gun
block, remove dried chemicals to make removal
easier.
11. Remove and clean check valves (see Remove
Check Valve, page 20).
12. Remove valving rod:
311338N
NOTICE
a. Use 3/8 in. wrench on hex-shaped valving rod
shank and a 1/2 in. wrench on jam nut to loosen
it and back it away from valving rod shank by 3
or 4 full turns.
b. Unthread valving rod from piston shaft and
remove.
13. Clean all components thoroughly before reassem-
bly.
14. Inspect gun block to ensure proper operation of
spray gun.
Install Centerline
Components
Before installation, ensure all gun components are clean
and dry. Lubricate all moving parts and threads.
1. To install valving rod, thread jam nut as far back on
piston shaft as possible. Screw shank end of valving
rod onto threaded end of piston rod.
2. Install rear seal and packing nut if removed. Thread
packing nut into gun block by hand, but do not
tighten.
3. To install gun block, carefully slide gun block onto
valving rod towards air cylinder. Use 5/16 in. nut
driver to install gun block onto gun block mounting
bracket.
4. Connect air supply to gun.
5. OPEN safety stop.
6. To install mixing module, hold down gun trigger and
slide module over end of valving rod. Make sure to
align keypin with slot in gun block. Keep gun trigger
depressed and proceed to step 7.
7. To install PCD, hold gun trigger in and place PCD
over mixing module. If installing a fan tip, position
PCD according to which spray direction is needed
(vertical or horizontal). Keep gun trigger depressed
and proceed to step 8.
NOTE: Parts must align properly or chemical flow from
gun block ports will not enter mixing module when gun is
triggered.
Repair
21