Graco NXT User manual

Graco Inc. P.O. Box 1441 Minneapolis, MN 55440-1441
Copyright 2006, Graco Inc. is registered to I.S. EN ISO 9001
311238 rev. G
Instructions-Parts
NXT Air Motor
100 psi (0.7 MPa, 7.0 bar) Maximum Working Pressure
US and Foreign Patents Pending
See page 2 for model information.
Important Safety Instructions
Read all warnings and instructions in this manual.
Save these instructions.
#53
Conforms to
FM std 3600 & 3610
for use in Class I Div 1
Group D
T3C Hazardous locations
0359
II 1 G
EEx ia IIA T3
Nemko
06ATEX1124
Models with DataTrak™include
agency approvals listed below.
TI8621a
With Linear Sensor
Standard
WithDataTrak™

Models
2311238G
Contents
Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Air Motor Part No. Matrix . . . . . . . . . . . . . . . . . . . 2
Air Motor Part Nos. . . . . . . . . . . . . . . . . . . . . . . . 3
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Component Identification . . . . . . . . . . . . . . . . . . . . 6
De-icing Control (F) . . . . . . . . . . . . . . . . . . . . . . . 7
Integrated Air Control Module Accessory . . . . . . 7
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
DataTrak Controls and Indicators . . . . . . . . . . . . . 8
DataTrak Operation . . . . . . . . . . . . . . . . . . . . . . . . . 9
Setup Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Run Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Replace the DataTrak Module Battery or Fuse . 12
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Preventive Maintenance Schedule . . . . . . . . . . 16
Tools Required . . . . . . . . . . . . . . . . . . . . . . . . . 16
Pressure Relief Procedure . . . . . . . . . . . . . . . . 16
Air Valve Repair . . . . . . . . . . . . . . . . . . . . . . . . 16
Cylinder and Piston Repair . . . . . . . . . . . . . . . . 20
Poppet Repair . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Replace the Linear Sensor (if present) . . . . . . . 23
Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Air Motor Parts Drawing
(Shown with DataTrak and Low Noise Exhaust)
24
Air Motor Parts Drawing (Shown with Linear Sensor)
25
NXT Model 2200 Air Motors . . . . . . . . . . . . . . . 26
NXT Model 3400 Air Motors . . . . . . . . . . . . . . . 27
NXT Model 6500 Air Motors . . . . . . . . . . . . . . . 28
Air Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Mounting Hole Diagrams . . . . . . . . . . . . . . . . . . . . 33
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Graco Standard Warranty . . . . . . . . . . . . . . . . . . . 38
Graco Information . . . . . . . . . . . . . . . . . . . . . . . . . 38
Models
Air Motor Part No. Matrix
Check your motor’s identification plate (ID) for the 6-digit part number of your motor. Use the
following matrix to define the construction of your motor, based on the six digits. For exam-
ple, Motor Part No. N65DT0represents an NXT motor (N), 6500 cc per stroke (6 5), with
de-icing exhaust (D) and DataTrak monitoring (T). The last digit (0) is unassigned. ID
N65 D T0
First Digit
(Motor) Second and Third Digits (motor size in cc per stroke) Fourth Digit (Exhaust Type) Fifth Digit (Data Monitoring) Sixth Digit (unassigned)
N (NXT
Air Motor) 65 6500 D De-icing N None 0 None assigned
34 3400 L Low noise T DataTrak
22 2200 R Remote (see note below) H Linear Sensor
Remote exhaust models have a 1 in. npt(f) exhaust
outlet, allowing installation of a muffler or plumbing
to route exhaust to a remote location. Do not operate the remote exhaust air motor without a
plumbed exhaust line or muffler installed.

Models
311238G 3
Air Motor Part Nos.
Air Motor
Part No. Series NXT Model
Piston
Diameter,
in. (mm) De-Ice Low Noise Remote Includes DataTrak™
Includes
Linear
sensor
N22DN0 D 2200 6.0 (152) ✔
N22DT0 D 2200 6.0 (152) ✔✔
N22DH0 D 2200 6.0 (152) ✔✔
N22LN0 D 2200 6.0 (152) ✔
N22LT0 D 2200 6.0 (152) ✔✔
N22LH0 D 2200 6.0 (152) ✔✔
N22RN0 D 2200 6.0 (152) ✔
N22RT0 D 2200 6.0 (152) ✔✔
N22RH0 D 2200 6.0 (152) ✔✔
N34DN0 D 3400 7.5 (191) ✔
N34DT0 D 3400 7.5 (191) ✔✔
N34DH0 D 3400 7.5 (191) ✔✔
N34LN0 D 3400 7.5 (191) ✔
N34LT0 D 3400 7.5 (191) ✔✔
N34LH0 D 3400 7.5 (191) ✔✔
N34RN0 D 3400 7.5 (191) ✔
N34RT0 D 3400 7.5 (191) ✔✔
N34RH0 D 3400 7.5 (191) ✔✔
N65DN0 D 6500 10.375 (264) ✔
N65DT0 D 6500 10.375 (264) ✔✔
N65DH0 D 6500 10.375 (264) ✔✔
N65LN0 D 6500 10.375 (264) ✔
N65LT0 D 6500 10.375 (264) ✔✔
N65LH0 D 6500 10.375 (264) ✔✔
N65RN0 D 6500 10.375 (264) ✔
N65RT0 D 6500 10.375 (264) ✔✔
N65RH0 D 6500 10.375 (264) ✔✔

Warnings
4311238G
Warnings
The following warnings are for the setup, use, grounding, maintenance, and repair of this equipment. The exclama-
tion point symbol alerts you to a general warning and the hazard symbols refer to procedure-specific risks. Refer
back to these Warnings. Additional, product-specific warnings may be found throughout the body of this manual
where applicable.
WARNING
FIRE AND EXPLOSION HAZARD
Flammable fumes, such as solvent and paint fumes, in work area can ignite or explode. To help prevent
fire and explosion:
• Use equipment only in well ventilated area.
• Eliminate all ignition sources; such as pilot lights, cigarettes, portable electric lamps, and plastic drop
cloths (potential static arc).
• Keep work area free of debris, including solvent, rags and gasoline.
• Do not plug or unplug power cords, or turn power or light switches on or off when flammable fumes
are present.
• Ground all equipment in the work area. See Grounding instructions.
• Use only grounded hoses.
• Hold gun firmly to side of grounded pail when triggering into pail.
• If there is static sparking or you feel a shock, stop operation immediately. Do not use equipment
until you identify and correct the problem.
• Keep a working fire extinguisher in the work area.
SKIN INJECTION HAZARD
High-pressure fluid from gun, hose leaks, or ruptured components will pierce skin. This may look like just
a cut, but it is a serious injury that can result in amputation. Get immediate surgical treatment.
• Do not point gun at anyone or at any part of the body.
• Do not put your hand over the spray tip.
• Do not stop or deflect leaks with your hand, body, glove, or rag.
• Do not spray without tip guard and trigger guard installed.
• Engage trigger lock when not spraying.
• Follow Pressure Relief Procedure in this manual, when you stop spraying and before cleaning,
checking, or servicing equipment.
PRESSURIZED EQUIPMENT HAZARD
Fluid from the gun/dispense valve, leaks, or ruptured components can splash in the eyes or on skin and
cause serious injury.
• Follow Pressure Relief Procedure in this manual, when you stop spraying and before cleaning,
checking, or servicing equipment.
• Tighten all fluid connections before operating the equipment.
• Check hoses, tubes, and couplings daily. Replace worn or damaged parts immediately.
MOVING PARTS HAZARD
Moving parts can pinch or amputate fingers and other body parts.
• Keep clear of moving parts.
• Do not operate equipment with protective guards or covers removed.
• Pressurized equipment can start without warning. Before checking, moving, or servicing equipment,
follow the Pressure Relief Procedure in this manual. Disconnect power or air supply.

Warnings
311238G 5
EQUIPMENT MISUSE HAZARD
Misuse can cause death or serious injury.
• Do not operate the unit when fatigued or under the influence of drugs or alcohol.
• Do not exceed the maximum working pressure or temperature rating of the lowest rated system
component. See Technical Data in all equipment manuals.
• Use fluids and solvents that are compatible with equipment wetted parts. See Technical Data in all
equipment manuals. Read fluid and solvent manufacturer’s warnings. For complete information
about your material, request MSDS forms from distributor or retailer.
• Check equipment daily. Repair or replace worn or damaged parts immediately with genuine Graco
replacement parts only.
• Do not alter or modify equipment.
• Use equipment only for its intended purpose. Call your Graco distributor for information.
• Route hoses and cables away from traffic areas, sharp edges, moving parts, and hot surfaces.
• Do not kink or over bend hoses or use hoses to pull equipment.
• Keep children and animals away from work area.
• Comply with all applicable safety regulations.
PERSONAL PROTECTIVE EQUIPMENT
You must wear appropriate protective equipment when operating, servicing, or when in the operating
area of the equipment to help protect you from serious injury, including eye injury, inhalation of toxic
fumes, burns, and hearing loss. This equipment includes but is not limited to:
• Protective eyewear
• Clothing and respirator as recommended by the fluid and solvent manufacturer
•Gloves
• Hearing protection
WARNING

Component Identification
6311238G
Component Identification
Key for FIG. 1
A Air Inlet, 3/4 npt(f)
B Bleed-Type Master Air Valve
C Air Regulator Adjustment Knob
D Air Pressure Gauge
E Air Filter (out of view; located at rear of air control kit)
F De-icing Control
G Air Valve (behind cover)
H DataTrak module (see pages 7-12; not present on all
models)
J Runaway Solenoid (component 1)
K DataTrak Sensors (component 2)
L Air Valve Inlet Port, 3/4 npt(f)
M Safety Relief Valve
FIG. 1: Component Identification (Model Shown with DataTrak Module and Accessory Air Control Kit)
TI8233b
H
KJ
F
G
A
Detail With Air Valve
Cover Removed
TI7759a
B
C
D
E
L
M

Grounding
311238G 7
De-icing Control (F)
Open with knob or flat blade screwdriver to reduce icing.
Integrated Air Control Module
Accessory
Bleed-type Master Air Valve (B)
• Required in your system to relieve air trapped
between it and the air motor when the valve is
closed.
• Be sure the valve is easily accessible from the pump
and located downstream from the air regulator.
Air Regulator (C)
Adjusts air pressure to the motor and fluid outlet pres-
sure of pump. Locate it close to the pump. Install a
gauge (D) to read air pressure.
Safety Relief Valve (M)
Automatically opens to relieve air pressure, to prevent
pump overpressurization.
Air Filter (E)
Removes harmful dirt from compressed air supply.
Grounding
The equipment must be grounded. Grounding reduces
the risk of static and electric shock by providing an
escape wire for the electrical current due to static build
up or in the event of a short circuit.
See FIG. 2. Use the ground screw (60) and lockwasher
(61) to attach Part No. 244524 Ground Wire (GW) at the
rear of the air motor. Tighten the screw securely. Con-
nect the other end of the ground wire to a true earth
ground.
Accessory Air Control Kits include air line compo-
nents in an integrated assembly. Order the kits sep-
arately. See manual 311239 for installation
instructions.
•NXT011 with locking air regulator and 110 psi
(0.76 MPa, 7.6 bar) relief valve
•NXT031 with locking air regulator and 75 psi
(0.51 MPa, 5.1 bar) relief valve
•NXT021 with non-locking air regulator and 110
psi (0.76 MPa, 7.6 bar) relief valve.
Trapped air can cause the pump to cycle unexpectedly,
which could result in serious injury from splashing or
moving parts.
TI8802aTI8159b
FIG. 2. Ground Wire
60, 61
TI8250a
GW

DataTrak Controls and Indicators
8311238G
DataTrak Controls and Indicators
Key for FIG. 3
T Runaway Limit, in cycles per minute (user settable;
00=OFF)
U Lower Displacement (user settable)
V Flow Rate Units (user settable to gpm [US], gpm
[Imperial], oz/min [US], oz/min [Imperial], l/min, or cc/min)
W LED (fault indicator when lit)
X Diagnostic Reference Card (see TABLE 1, page 11)
Y Display
PF Prime/Flush Key (Enables Prime/Flush mode. While in
Prime/Flush mode, runaway protection is disabled and the
batch totalizer [BT] will not count.)
RK Reset Key (Resets faults. Press and hold for 3 seconds to
clear the batch totalizer.)
CF Cycle/Flow Rate
BT Batch Totalizer
GT Grand Totalizer
RT Runaway Toggle (enable/disable)
UT E1 Toggle
DT E2 Toggle
ST E5 Toggle
DataTrak is included with certain models. See page
2 for a list of models featuring DataTrak.
/min,
FIG. 3. DataTrak Controls and Indicators
X
W
Y; See Details at right.
CF BT
GT
V
RT
T
PF
RK
U
UT
DT
ST
Run Mode
Setup Mode
TI8215a
TI8622b
TI8623b
RK
PF

DataTrak Operation
311238G 9
DataTrak Operation
Setup Mode
1. See FIG. 3. Press and hold for 5 seconds until
Setup menu appears.
2. To enter settings for runaway, lower size, and flow
rate units, and to enable runaway, E1, E2, and E5
error options, press to change the value, then
to save the value and move the cursor to the
next data field.
3. Move the cursor to the E5 error enable option field,
then press once more to exit Setup mode.
Run Mode
Runaway
1. See FIG. 3. If pump runaway occurs, the runaway
solenoid will actuate, stopping the pump. The LED
(W) will flash and the display (Y) will indicate a run-
away condition (see Table 1).
2. To reset runaway monitor, close master air valve (B).
Wait for air to completely bleed off the air motor
before going to step 3. The screen will change to
indicate this, as shown below.
3. Press to clear the diagnostic code and reset the
runaway solenoid.
4. Open master air valve (B) to restart pump.
DataTrak is included with certain models. See page
2 for a list of models featuring DataTrak.
The DataTrak display (Y) will turn off after 1 minute
to save battery life. Press any key to wake up the
display.
Graco recommends setting runaway to 60 .
When runaway, E1, E2, and E5 error options are
enabled, a ✓will appear on the setup screen. See
FIG. 3.
To disable runaway monitoring, go to setup mode
and set runaway value to 0 (zero) or toggle (RT) off
(see FIG. 3).
B

DataTrak Operation
10 311238G
Prime/Flush
1. See FIG. 3. To enter Prime/Flush mode, press any
key to wake up the display, then press . The
Prime/Flush symbol will appear in the display and
the LED will flash .
2. While in Prime/Flush mode, runaway protection is
disabled and the batch totalizer (BT) will not count.
3. To exit Prime/Flush mode, press any key to wake up
the display, then press . The Prime/Flush sym-
bol will disappear from the display and the LED will
stop flashing.
Counter/Totalizer
See FIG. 3. The last digit of the batch totalizer (BT) rep-
resents tenths of gallons or liters. To reset the totalizer,
press any key to wake up the display, then press and
hold for 3 seconds.
Display
See FIG. 3. The display (Y) will turn off after 1 minute of
inactivity in Run mode or 3 minutes in Setup mode.
Press any key to wake up the display.
Diagnostics
DataTrak can diagnose several problems with the pump.
When the monitor detects a problem, the LED (W, FIG.
3) will flash and a diagnostic code will appear on the dis-
play. See Table 1.
To acknowledge the diagnosis and return to the normal
operating screen, press once to wake up the display,
and once more to clear the diagnostic code screen.
If flow rate is set to both totalizers will dis-
play the number of pump cycles.
/min,
DataTrak will continue to count cycles when display
is off.
The display (Y) may turn off if a high-level static dis-
charge is applied to the DataTrak. Press any key to
wake up the display.

DataTrak Operation
311238G 11
Table 1: Diagnostic Codes
Symbol Code
No. Code Name Diagnosis Cause
Runaway Pump running faster than set runaway
limit. • Increased air pressure. • Increased fluid output.
• Exhausted fluid supply.
E-1 Diving Up Leak during upstroke. Worn piston valve or packings.
E-2 Diving Down Leak during downstroke. Worn intake valve.
E-3 Low Battery Battery voltage too low to stop
runaway. Low battery. To replace battery, see page 12.
E-4 Service
Component 1 Problem with stopping runaway. • Damaged solenoid. • Damaged valve carriage.
E-4 Disconnected
Solenoid Solenoid is disconnected. • Solenoid unplugged. • Damaged solenoid wires.
E-5 Service
Component 2 Problem with sensing valve movement. • Sensors unplugged. • Sensors mounted incorrectly.
• Damaged sensors.
• Damaged valve carriage.
E-6 Blown Fuse Fuse is blown. • Faulty solenoid or solenoid wiring.
• Extreme temperatures (above 140°F
[60°C]).

DataTrak Operation
12 311238G
Replace the DataTrak Module
Battery or Fuse
1. Remove two screws (135). Carefully slide the
DataTrak module (131) out of the housing (132).
See FIG. 4.
2. Disconnect the runaway solenoid and sensor cables
from the module board. See FIG. 5.
3. Take the DataTrak module (131) to a non-hazardous
location.
4. To replace the battery, disconnect the used battery
and replace with an approved battery.
5. To replace the fuse (131a):
a. Remove the screw, metal strap, and plastic
holder.
b. Pull the fuse away from the board.
c. Replace with a new fuse (131a).
The battery and fuse must be replaced in a non-haz-
ardous location.
FIG. 4. Remove DataTrak Module
Use only the following approved replacement batter-
ies. Use of an unapproved battery will void Graco’s
warranty and FM and Ex approvals.
• Ultralife lithium # U9VL
• Duracell alkaline # MN1604
• Energizer alkaline # 522
• Varta alkaline # 4922
132
131
135
TI8216b
Use only a Graco-approved replacement fuse (131a).
FIG. 5. DataTrak Battery and Fuse Location
SolenoidCable
Connection
Battery
Fuse (131a)
SensorCable
Connection
TI7757a

DataTrak Operation
311238G 13

Troubleshooting
14 311238G
Troubleshooting
Problem Cause Solution
Air motor will not run. DataTrak solenoid engaged. Dam-
aged main air valve spool or pop-
pets.
Rebuild main air valve. See page 16.
Replace poppets (12). See page 22.
Runaway occurred (DataTrak mod-
els only). See Runaway on page 9.
Air continuously exhausting around
air motor shaft. Damaged air motor shaft seal. Replace air motor shaft seal (7). See page 20.
Air continuously exhausting from
muffler. De-icing control is open. Close de-icing control with knob or flat blade screwdriver.
Damaged air valve carriage, plate,
or seal. Replace the carriage (108), plate (105), or seal (104). See page 18.
Air motor “bounces” at top of stroke. Damaged bottom poppet. Replace bottom poppet (12). See
page 22.
Air motor “bounces” at bottom of
stroke. Damaged top poppet. Replace top poppet (12). See page 22.
Slow motor reversal. Plugged poppet muffler. Remove muffler (58) and clean.
Icing on muffler. Air motor operating at high pressure
or high cycle rate. Reduce pressure, cycle rate, or duty cycle of motor, or open de-icing con-
trol with knob or flat blade screw-
driver.

Troubleshooting
311238G 15
FIG. 6. Cutaway View, Standard and DataTrak Models
TI8624a
Poppet
Poppet Piston Shaft SealsPiston O-ring
Air Valve
Seals
Air Valve
Spool
Air Valve
Slide Plate
Air Valve
Seals
FIG. 7. Cutaway View, Models with Linear Sensor
TI8066b
Poppet
Poppet Piston Shaft SealsPiston O-ring
Air Valve
Seals
Air Valve
Spool
Air Valve
Slide Plate
Air Valve
Seals
Linear Sensor

Repair
16 311238G
Repair
Preventive Maintenance
Schedule
The operating conditions of your particular system
determine how often maintenance is required. Establish
a preventive maintenance schedule by recording when
and what kind of maintenance is needed, and then
determine a regular schedule for checking your system.
Tools Required
• Flat blade screwdriver
• Phillips screwdriver
• 3/4 in. socket wrench
• 9/16 in. socket wrench
• 3/8 in. socket wrench
• Torque wrench
•Grease
• Thread adhesive
Pressure Relief Procedure
1. Engage the trigger lock.
2. Close the bleed-type master air valve.
3. Disengage the trigger lock.
4. Hold a metal part of the gun firmly to a grounded
metal pail. Trigger the gun to relieve pressure.
5. Engage the trigger lock.
6. Open all fluid drain valves in the system, having a
waste container ready to catch drainage. Leave
drain valve(s) open until you are ready to spray
again.
7. If you suspect the spray tip or hose is clogged or
that pressure has not been fully relieved after follow-
ing the steps above, VERY SLOWLY loosen tip
guard retaining nut or hose end coupling to relieve
pressure gradually, then loosen completely. Clear
hose or tip obstruction.
Air Valve Repair
Remove the Air Valve
1. Stop the pump at the middle of its stroke. Relieve
the pressure, page 16.
2. Disconnect the air line to the motor.
3. See FIG. 8. Pry off the top cover (30).
Trapped air can cause the pump to cycle unexpectedly,
which could result in serious injury from skin injection
or moving parts.
Do not lift or move motor while pressurized.
FIG. 8. Remove the Top Cover
TI8218b
30

Repair
311238G 17
4. Remove the poppet assemblies (12). See Poppet
Repair, page 22.
5. See FIG. 9. Remove the outer valve cover (47).
6. For motors with DataTrak or the linear sensor:
a. DataTrak Models: Remove the two screws
(135). Carefully remove the DataTrak module
(131), see page 12. 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 FIG. 14 on page 23.
7. Remove the four muffler screws (43) and the four
screws (41). Remove the air valve (40). Inspect the
gaskets (46).
8. To repair the air valve, go to Disassemble the Air
Valve, page 18. To install a complete new air valve,
continue with step 9.
9. Lubricate the gaskets (46) and ensure they align
with the holes at the back of the air valve (40). Install
the air valve. Thread the muffler screws (43) in by
hand. Install the screws (41) and torque to 15 ft-lb
(20.3 N•m). Torque the muffler screws (43) to
120-135 in-lb (13.6-15.2 N•m).
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 FIG. 14, page 23.
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. Install the poppet assemblies (12). See Poppet
Repair, page 22.
12. Reinstall the top cover (30).
13. Reconnect the air line to the motor.
FIG. 9. Remove the Air Valve (Model Shown with DataTrak Module)
TI8217b
47
41
40
43
43
46
Apply lubricant.
Thread in by hand, then torque to
40 in-lb (4.5 N•m).
Torque to 15 ft-lb (20.2 N•m).
Thread in by hand, then torque to
100 in-lb (11.3 N•m).
5
6
11
17
17
5
11
17
132
134
6
131
135

Repair
18 311238G
Disassemble the Air Valve
1. Perform steps 1-7 under Remove the Air Valve,
page 16.
2. See FIG. 11. Remove the screws (124), carriage
cover (112), spring-loaded detent (113), gasket
(106), and de-icing control (145).
3. See FIG. 10. Remove the retainer pins (111) from
their holes (J). Invert the pins and slide the heads
into the slots on the piston stops (110). Use the pins
to pull the piston stops out.
4. See FIG. 11. Hold the bolt (118) with a 9/16 in.
socket wrench while unscrewing the nut (121) with
another wrench. Disassemble the piston bolt
assembly. Inspect the u-cup packings (127) and all
o-rings (109a, 110a, 128). Replace any damaged
parts.
5. Remove the sleeves (109).
6. Remove the carriage (108) and carriage detent
(107).
7. Remove the screws (123), retainers (117), valve
plate (105), and seal (104).
8. Inspect the detent (107), carriage (108), plate (105),
and seal (104) for damage.
Reassemble the Air Valve
1. If the valve body (103) was removed, install a new
gasket (102†‡).
2. Lubricate the valve plate (105‡). Install the seal
(104†‡) and plate (105‡) in the valve body (103).
Lubricate the sealing face of the carriage (108‡).
Install the carriage, detent (107‡) and retainers
(117). Thread the screws (123) in by hand, then
torque to 12 ft-lb (16.3 N•m).
3. Install the sleeves (109‡).
4. Be sure to lubricate both ends of the piston bolt
(118). Assemble the piston bolt assembly exactly as
shown in FIG. 11, following all assembly notes.
5. Hold the bolt (118) with a wrench while tightening
the nut (121) with another wrench. Torque to 34-38
ft-lb (45.9-51.3 N•m).
6. Install the piston stop (110) and retainer pins (111).
7. For motors with DataTrak or the linear sensor, rein-
stall the modules, see step 10, page 17.
8. See FIG. 11. Lubricate and install the spring-loaded
detent (113‡), gasket (106†‡), carriage cover (112),
and screws (124). Torque to 100 in-lb (11.3 N•m).
9. See FIG. 9, page 17. Lubricate the gaskets (46) and
ensure they align with the holes at the back of the
air valve (40). Install the air valve. Thread the muf-
fler screws (43) in by hand. Install the screws (41)
and washers (34) and torque to 15 ft-lb (20.3 N•m).
Torque the muffler screws (43) to 100 in-lb (11.3
N•m).
Air Valve Seal Repair Kit NXT135 is available. Parts
included in the kit are marked with a symbol (†). For
the best results, use all the parts in the kit.
Air Valve Rebuild Kit NXT136 is available. Parts
included in the kit are marked with a symbol (‡). For
the best results, use all the parts in the kit.
FIG. 10. Remove Piston Stops
TI7758a
111
J
110
CAUTION
Do not separate the valve body (103) from the
exhaust cover (101) unless the air porting is plugged.
Separating these parts may damage the gasket (102).

Repair
311238G 19
FIG. 11. Air Valve Repair (NXT107 Shown)
TI7751e
110
†‡127
‡129
118
†‡128
102†‡
101
104†‡
105‡
117
123
108‡
107‡
110
109‡
121
119
120
111
‡113
124
138
140 †‡142
112
†‡106
111
103
130‡
129‡
128†‡
127†‡
145†
139
144
119
120
Apply lubricant.
Important: Lubricate both ends of bolt (118) and torque to
34-38 ft-lb (45.9-51.3 N•m).
Lips must face up.
Lips must face down.
Torque to 100 in-lb (11.3 N•m).
Thread in by hand, then torque to 12 ft-lb (16.3 N•m).
1
2
3
4
5
7
7
5
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
3
4
Deta
i
l o
f
P
i
ston Bolt
(
118
)
4
120 1
119 13
118 2
121 2
TI7774a
‡109
109a
110a
109a
110a
1
1
1
1

Repair
20 311238G
Cylinder and Piston Repair
Disassemble the Air Motor
1. Stop the pump at the middle of its stroke. Relieve
the pressure, page 16.
2. Disconnect the air line to the motor.
3. See FIG. 8 on page 16. Pry off the top cover (30).
4. Remove the outer valve cover (47). See FIG. 12.
5. Remove the top two muffler screws (43) and the top
two screws (41). Loosen but do not remove the bot-
tom two muffler screws (43) and the bottom two
screws (41). Tilt the air valve (40) to make disas-
sembly easier.
6. For motors with DataTrak or the linear sensor:
a. DataTrak Models: Remove the two screws
(135). Carefully remove the DataTrak module
(131), see page 12. 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 FIG. 14 on page 23.
7. Loosen the tie bolts (13). Using a rubber mallet, hit
the underside of the top cap (1) to separate. Lift the
top cap and bolts (13) off motor.
8. Disconnect the air motor from the lower (see your
separate pump manual). Leave the piston shaft
adapter (A) attached to the shaft (S).
9. Push the piston assembly (4) out the top of the cyl-
inder (2).
10. 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).
11. Remove the cylinder (2). Check the inner surface for
scoring or other damage. Replace if damaged.
12. 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. If the bearing is
damaged, replace the bottom cover (3).
Air Motor Seal Repair Kits are available. See the
parts lists on pages 26, 27, and 28 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.