Graco 3A8693C, Instructions Manual

Page: 21 / 34

Repair
3A8693C 21
Air Valve Repair
Tools Required:
• Torque wrench
• Torx (T20) screwdriver
or 7 mm (9/32 in.) socket wrench
• Needle-nose pliers
• O-ring pick
• Lithium-base grease, part no. 111920 (Lubriplate
630AA or equivalent)
Air valve repair kit 236273 is available. Use all parts in
the kit for best results. See Parts , starting on page 25.
Service the air valve as follows. See F
IG
. 10–F
IG
. 13.
Disassemble Air Valve
1. Perform the Pressure Relief Procedure , page 12.
2. Disconnect all air and fluid lines from the
equipment.
3. Use an applicable screwdriver or wrench to remove
the screws (3) from the valve cover (2) on the center
housing (1). Remove valve cover (2) and gasket (4)
from center housing (1).
4. Move the valve carriage (5) to the center position
and pull it out of the cavity.
5. Remove the valve block (7) and o-ring (6) from the
carriage.
6. Use a needle-nose pliers to pull the pilot block (18)
straight up and out of the cavity. See F
IG
. 11.
7. Pull the actuator pistons (11) out of the bearings
(12). See F
IG
. 12.
8. Remove the u-cup packings (10) from the pistons.
Pull the pilot pins (16) out of the bearings (15).
9. Remove the o-rings (17) from the pilot pins.
10. Inspect the valve plate (8). If damaged, use an
applicable screwdriver or wrench to remove the
screws (3). Remove the valve plate (8) and seal (9).
See F
IG
. 13.
11. Inspect the bearings (12, 15). If damaged, follow
Replace Bearing and Air Gasket , page 23.
NOTE: Do not remove undamaged bearings.
12. Clean and inspect all parts for wear or damage.
Replace as needed.
F
IG
. 10: Air Valve Access
F
IG
. 11: Air Valve Carriage
Torque to 50–60 in-lb (5.6–6.8 N•m).
4
2
1
3
1
1
5
11
16
1
2
Grease.
1
2
Grease lower face.
2
18
7
6
12
15