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

Operation Basics

Valving Rod Adjustment

Valving rod should not require adjustment if it was
shipped from factory with mixing module and PCD in-
stalled. Valving rod should only require 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
19.
2. Connect air supply to gun.
3. Use 5/16 in. open-end wrench to loosen packing nut
3 or 4 turns. This relieves pressure between seals
and makes adjustment easier.
F . 10: Valving Rod Adjustments
IG
14
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 spherical 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. Re-tighten packing nut.
8. Check rear safety stop by attempting to disengage
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 disengages, 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 re-tighten if necessary.
NOTE: If valving rod required adjustment as part of ini-
tial mixing module and PCD installation on a new spray
gun, proceed to Initial Set Up, page 15.
311338N