Poppet Repair - Graco NXT Instructions Manual

Repair
Reassemble the Air Motor
1. See F . 12. Install one backup packing (8*), the
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v-packing (7*) with the lips facing up, the second
backup packing (8*), and the retaining ring (9*) in
the bottom cover (3). Lubricate the packings. Install
the bumper (59).
2. Install the o-ring (17*) on the piston (4). Ensure the
piston bumper (10) is in place.
3. Install the piston assembly on the bottom cover (3),
carefully sliding the adapter (A) and shaft (S)
through the bearing (B).
4. Grease the inside of the cylinder (2). Place the cylin-
der (2) over the piston (4).
5. Carefully place the top cap on the cylinder (2) so the
flat edge aligns with the flat edge of the bottom
cover (3). Install the tie bolts (13) hand tight.
6. Reinstall the top two screws (41) and torque to 15
ft-lb (20.3 N•m).
7. Torque tie bolts (13) to 38-42 ft-lb (51.3-56.7 N•m).
8. Retighten the bottom two screws (41) and torque to
15 ft-lb (20.3 N•m).
9. Reconnect the air motor to the lower (see your sep-
arate pump manual).
See Accessories, page 32, for a list of available
adapters to connect the NXT motor to various
Graco lowers.
10. For motors with DataTrak or the linear sensor:
a. DataTrak Models: Carefully slide the housing
(132) onto the air valve. Thread the screws
(134) in by hand, then torque to 40 in-lb (4.5
N•m). Reattach the solenoid and sensor cables
to the DataTrak module (131), see page 12.
Carefully slide the module back into the housing
(132). Reinstall the two screws (135).
b. Linear Sensor Models: Reconnect the sensor
cable to the circuit board. See F
Carefully slide the housing (132) onto the air
valve. Thread the screws (134) in by hand, then
torque to 40 in-lb (4.5 N•m).
11. Reinstall the muffler screws (43) by hand, then
torque to 100 in-lb (11.3 N•m).
22
12. Reinstall the outer valve cover (47).
13. Reinstall the top cover (30).
14. Reconnect the air line to the motor.

Poppet Repair

1. Stop the pump at the middle of its stroke. Relieve
2. Disconnect the air line to the motor.
3. See F
4. See F
5. Inspect the poppet o-rings (12a, 12b, 12d) and
6. Lubricate the poppet assemblies (12) and reinstall
. 14, page 23.
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F . 13. Poppet Detail
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the pressure, page 7.
. 8 on page 16. Pry off the top cover (30).
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. 13. Unscrew the poppet assemblies (12).
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The small o-rings (12c, 12d) may not come out with
the poppet assemblies. Be sure to remove them
from the top cap (1) or bottom cover (3).
backup (12c). Replace damaged o-rings, or replace
the entire poppet assembly.
in the top cap (1) and bottom cover (3). Torque to
38-42 ft-lb (51.3-56.7 N•m).
12b
12a
12c
12d
TI7750b
311238G