Graco N22DH0, Instructions-Parts List Manual

Page: 24 / 48

Repair
24 311238ZAM
Cylinder and Piston Repair
Disassemble the Air Motor
1. Stop the pump at the middle of its stroke. Relieve
the pressure, page 20.
2. Disconnect the air line to the motor.
3. See F
IG
. 8 on page 20. Pry off the top cover (30).
4. For motors with DataTrak or the linear sensor:
a. DataTrak Models: Remove the two screws
(135). Carefully remove the DataTrak module
(131), see page 14. Disconnect the runaway
solenoid and sensor cables from the module
board. Remove the two screws (134) and care-
fully slide the housing (132) off the air valve.
b. Linear Sensor Models: Remove the screws
(134) and carefully slide the housing (132) off
the air valve. Disconnect the sensor cable from
the circuit board. See F
IG
. 15 on page 28.
5. Remove the outer valve cover (47). See F
IG
. 12.
6. Remove the four screws (43) and the muffler (15).
7. Remove the top two air valve screws (41). Loosen
but do not remove the bottom two screws (41). Tilt
the air valve (40) to make disassembly easier.
8. Remove the tie bolts (13). Using a rubber mallet, hit
the underside of the top cap (1) to separate. Lift the
top cap off the motor.
9. Disconnect the air motor from the lower (see your
separate pump manual). Leave the piston shaft
adapter (A) attached to the shaft (S).
10. Push the piston assembly (4) out the top of the cyl-
inder (2).
11. Inspect the piston o-ring (17). Check the piston (4)
and piston shaft (S) for scoring or damage. The
replacement piston (4) includes the piston, shaft (S),
adapter (A), and bumper (10).
12. Remove the cylinder (2). Check the inner surface for
scoring or other damage. Replace if damaged.
13. Remove the bumper (59), retaining ring (9), backup
packings (8), and v-packing (7) from the bottom
cover (3). Inspect these parts for wear or damage.
Inspect the bearing (B) in place (slight scoring is
acceptable). If the bearing is damaged, replace the
bottom cover (3).
Air Motor Seal Repair Kits are available. See the
parts lists on pages 32, 34, and 36 for the correct
kit for your size motor. Parts included in the kits are
marked with an asterisk (*). For the best results,
use all the parts in the kit.