Valving Rod Adjustment - Graco GX-8 Operation, Parts, Service, Repair

Valving Rod Adjustment

Valving rod should not require adjustment if it
was shipped from factory with mixing module
and PCD installed. Valving rod should only re-
quire adjustment when:
• Piston/rod assembly/ring is changed
• Valving rod is changed
• PCD is installed or changed
• Mixing module is installed or changed
To adjust valving rod:
1. Perform Clean Spray Gun Procedure,(see
page 15.
2. Connect air supply to gun.
3. Use 5/16 in. open-end wrench to loosen
packing nut 3 or 4 turns. This relieves pres-
sure between seals and makes adjustment
easier.
F . 10: Valving Rod Adjustments
IG
311338B
Valving Rod
Assembly
Packing
Jam Nut
Nut
4. Use 3/8 in. wrench on hex-shaped valving
rod shank and 1/2 in. wrench on jam nut to
loosen and back it away from valving rod by
3 or 4 full turns. Then move valving rod
toward gun cylinder. Turn valving rod shank
2 or 3 full turns clockwise.
5. Slowly turn valving rod counterclockwise to
move it toward PCD until resistance is felt.
Valving rod tip should touch inside spheri-
cal surface of PCD.
6. Carefully maintain 3/8 in. wrench in position
and tighten jam nut up against valving rod
shank to lock adjustment into place.
7. Retighten packing nut.
8. Check rear safety stop by attempting to dis-
engage it. If knob will not turn, valving rod
is adjusted too far forward. Repeat steps 3 -
7. Make sure not to adjust valving rod past
the point resistance is felt. If safety stop dis-
engages, proceed to step 9.
9. Trigger gun with safety stop disengaged to
confirm rear seal adjustment. Make sure
rod moves freely. If not, loosen packing nut
slightly until it does. Start to spray and
check for chemical seepage from packing
nut and retighten if necessary.
If valving rod required adjustment as part of
initial mixing module and PCD installation
on a new spray gun, proceed to Initial Set
Up, page 12.
Operation Basics
11