Diffuser Seat Replacement; Reassembly - Graco PerformAA 26B570 Instructions Manual

Service

Diffuser Seat Replacement

Clean parts with a solvent that is compatible with the
parts and the fluid being sprayed. See Kits and
Accessories, page 37.
1. Follow the Pressure Relief Procedure, page 14.
2. Remove gun from manifold.
3. Remove the air cap retaining ring (8), air cap (30),
and spray tip (9).
4. Trigger the gun (or remove cap (27) and springs
(28, 29)) to pull the needle housing off the seat while
you unscrew the diffuser (10) from the gun body (1).
5. Inspect the o-rings (10d, 10e, 10f) in place.
Carefully remove the o-rings from the diffuser
housing (10) and replace if necessary.
6. Remove the seat nut (10c), seat (10b) and seat
gasket (10g) (Carbide seat only) using a 7/32 in.
hex wrench.
7. Inspect the seat (10b) and seat gasket (10g) and
replace if necessary.
8. Reinstall the seat gasket (10g) (Carbide seat only),
seat (10b), and seat nut (10c). Torque to 45-50 in-lb
(5.1-5.7 N•m). Be sure not to overtighten the nut.
NOTE: When reinstalling the carbide seat, the tapered
end of the seat (red side) must point toward the gun tip.
The plastic seat, standard in Model 26B572, can be
reinstalled in either direction. However, do not reverse
the direction of the seat if it is worn; it must be replaced.

Reassembly

1. Guns in a Non-circulating only: Lubricate the
backup o-ring (7†) and o-ring (6†) and install them
on the fluid outlet port plug (5). Install the plug in the
fluid outlet port of the fluid housing (2). See F
2. All guns: Reinstall the gasket (4) in the fluid
housing (2).
3. Install the o-rings (22, 23) on the piston (20). Install
two o-rings (25, 26) on each of the piston stems.
Lubricate all the o-rings, the piston, and the piston
stems.
24
4. Align the gasket (15) as shown in the exploded view
in Fig. 8.
If replacing gasket (15), place the gasket on the
piston housing (1), then install the fluid housing (2).
Torque the two screws (18) to 30 in-lb (3.4 N•m)
5. Insert the piston (20) into the piston housing (1).
6. Remove the protective paper from the sticky side of
the gasket (16) and adhere the gasket to the bottom
of the piston housing (1), making sure the three
holes in the gasket are properly aligned with the
matching holes in the housing.
Be sure to keep the needle straight when installing it in
the piston housing. If the needle is bent it must be
replaced.
7. Insert the needle assembly (14) into the front of the
fluid housing (2). Tighten to 50-60 in-lb (5.7-6.8
N•m).
8. Lubricate the threads of the diffuser-seat (10).
Screw it into the fluid housing (2) and torque to 65
in-lb (7.3 N•m).
9. Install the needle stop (21) on the needle. Coat the
setscrew (19) with semi-permanent anaerobic
sealant and install the screw into the needle stop.
Torque to 4-5 in-lb (0.45-0.56 N•m). Pull on the
needle to make sure it seats fully.
10. Install the springs (28, 29).
11. Lubricate the threads of the piston housing (1).
Screw the cap (27) onto the housing until it bottoms
out.
12. Assemble the standard tip and air cap.
Model 26B573: Install the RAC housing (11) and
RAC spray tip (9) in the RAC air cap assembly (30).
. 1.
IG
Position the blue tip guard as desired and screw the
air cap assembly onto the gun until it bottoms out.
See Reverse-A-Clean® (RAC) Spray Tip Setup,
page 13.
13. Reinstall the gun on the manifold with the four
screws (17). Torque to 65 in-lb (7.3 N•m).
NOTICE
3A8553A