Airdog CUMMINS ISX15 User manual

INDUSTRIAL
Fuel Air Separation System
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INSTALLATION MANUAL
For Trucks Equipped with
CUMMINS®ISX15 Common Rail & X15
Part No. A3SPBT453
NOW WITH DEMAND FLOW
Providing “Test Cell Performance” in “Real World Conditions” Since 1993!
Proudly Made in the USA
www.airdogdiesel.com
1-573-635-0555 or
1-877-463-4373
PLEASE READ
THESE INSTRUCTIONS
THOROUGHLY
BEFORE BEGINNING
INSTALLATION
Revised 3/25/20

2
THE RIGHT CHOICE FOR YOUR DIESEL ENGINE
CARB Executive Orders D-595-3 & D-595U-4 permit the advertisement, sales and installation of
PureFlow Technologies AirDog®Diesel Fuel Systems in California on 2016 and older model year
on-road diesel vehicles and o-road diesel vehicles/equipment.
Low Fuel Pressure Switch
and LED Indicator
Lets you know when to service
the fuel lter and water separator
before suering power loss.
NO MORE GUESSING!
4G-HD Fuel Pump
Pump shaft, stabilized with bearings on each end, holds the gerotor in virtually perfect
alignment for quiet running and extended longevity!
LoveJoy Coupler System
The LoveJoy Coupler System is
self-aligning and eliminates
virtually all vibrations.
Dual Port Pump
Balances the gerotor for quiet
operation and higher ows.
Protective Wire Screen
In water separator nipple.
6 Micron Particulate Filters
Long-Lasting MicroGlass Media
Water Separator/Prelter
Long-Lasting Wire Mesh Media
Bearings
Positive Air Separation
with primary air discharge port.
Demand Flow System
Easy installation, only one small line
connected to the engine return line to
return air/vapor to the tank.
Adjustable Regulator
For just the right fuel pressure.
INDUSTRIAL
Fuel Air Separation System

3
SYSTEM OVERVIEW
Welcome to the AirDog®Heavy Duty Industrial
Fuel Air Separation System for Class 8 Trucks
The AirDog®, with ADVANCED FUEL AIR SEPARATION, DEMAND FLOW, ADJUSTABLE
REGULATOR, LOW PRESSURE SENSOR with LED INDICATOR and the 4G-HD FUEL
PUMP, is a premium fuel ltration and delivery system for the Cummins ISX15 Common Rail &
X15 Diesel Engines.
The “VACUUM FEED FILTER SYSTEM” currently on your engine passes entrained air to the
engine and increases cavitation and vapor as the fuel lter plugs with use!
With Air & Vapor present in the fuel, the eective stroke of the High Pressure Pump and output
volume of fuel to the Common Rail is reduced. This adversely aects both the injection rate and
also the shape of the injection spray pattern, which results in increased fuel consumption and
increased exhaust emissions.
AirDog®removes the entrained air from the fuel and prevents the formation of vapor in the high
pressure pump to restore the eciency of the Common Rail System.
Diesel engines, regardless of which type of fuel injection system they may have, when equipped
with the AirDog®, can now perform as designed, delivering “test cell” performance while in “real
world” use!
The AirDog®removes water, particulates and most importantly, the entrained air from the
fuel owing to your engine. The entrained air and vapor separated from the fuel is returned to
the fuel tank. The fuel ow to the engine’s transfer pump is maintained at a NET POSITIVE
PRESSURE HEAD preventing cavitation and the formation of vapor thus overcoming the
performance related problems from plugged fuel lters, torque loss at higher engine RPM, and
high altitude operation.
All AirDog®products are manufactured with a personal touch,
unsurpassed attention to detail and the most stringent quality assurance!
TYPICAL INSTALLATION LAYOUT
Figure 1
The AirDog®requires only one small return line connected to the engine return line, for quick
and easy installations.
Pure Fuel to Engine
at Positive Pressure Entrained Air in Fuel
from Agitation & Sloshing
AirDog®Air/Vapor Return Line
Fuel Supply Line
Engine Air/Vapor Return Line

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AirDog®FPII-200 Cummins®ISX15 & X15
TABLE OF CONTENTS
Section 1……..……....………………….……..…....…..…................Table of Contents
Section 2……..…...…...............…...…..................…Installation and Safety Guidelines
Section 3……..……...……….....…….…...............……….……………....….Parts List
INSTALLATION PROCEDURES
Section 4…….…….…..……….....…..................Selecting the Best Mounting Location
Section 5A & B………...…..……….........Mounting the AirDog®& Mounting Brackets
Fuel Lines, Fittings & Low Fuel Pressure Sensor Switch
Section 6A........................................................................Fittings & Fuel Pressure Sensor
Section 6B….….…..…....…..........................................AirDog® Air/Vapor Return Line
Section 6C……..….....................................................Fuel Line from Tank & to Engine
Wiring Harness
Section 7…..….……....…..……………..………....…….............….......Wiring Harness
Section 8..……….…..……….…………................….…….…...........…Initial Start Up
Maintenance
Section 9..………...…….….……...........................................................…Filter Service
Section 1 Table of Contents

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 2 Installation & Safety Guidelines
The installation of your AirDog®can be made relatively easy by following the steps outlined in this
manual, and:
1. Inventory the package components. Immediately notify PureFlow® Technologies, Inc.,
of any missing or damaged parts.
2. Read the installation manual completely. Understand how the system operates and the
installation recommendations before beginning.
3. Proper location of the AirDog® on the vehicle is essential. Consider hazards presented to
the equipment by road debris and the elements.
4. The installation recommendations and guidelines contained herein are suggestions only.
Individual installations may vary.
5. Use diesel compatible thread sealer when installing ttings with NPT threads.
(Loctite® 545 Thread Sealer is diesel compatible.)
DO NOT REMOVE FACTORY INSTALLED SECONDARY FUEL FILTERS.
REMOVAL OF A FACTORY INSTALLED SECONDARY FUEL FILTER
MAY VOID YOUR ENGINE WARRANTY.
SAFETY GUIDELINES
CAUTION: Chock the vehicle’s tires to prevent rolling.
CAUTION: Disconnect the battery cables before proceeding with the AirDog® installation.
CAUTION: Wear safety glasses when operating power tools such as drills and grinders or when
using a punch or chisel.
CAUTION: Do Not drill into or weld the top of the frame rail or within 1-½” of the frame rail
ange on the side of the frame rail.
CAUTION: Route the fuel lines and electrical harnesses keeping them away from hot exhaust
components and/or moving parts. Properly secure the fuel lines and electrical
harnesses to prevent chang.
If you are uncertain of any installation procedure, please call:
PureFlow®Technologies, Inc. at 573-635-0555 for technical assistance.
NOTE: The pictures used in this manual are for example only and may not depict
the exact components as found on your truck.

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AirDog®FPII-200 Cummins®ISX15 & X15
PLEASE NOTE Due to the many variables in components and arrangement of those components
in the many dierent truck models, the AirDog® installation kit contains only the basic fuel ttings
needed to install the AirDog® using existing fuel lines.
Section 3 Parts List
1 16 mm M ORB x 16 mm F ORB x 908-09-0100-M
#6 M JIC Air/Vapor Return Fitting
(Available only from PureFlow Technologies)
2 # 6 F JIC Swivel x 3/8” Pushlock Hose Barb 4A-1-09-06-06-B
1 #6 F JIC Swivel x #6 M JIC Swivel 90° Elbow 4A-2-04-06-06-S
908-01-0453-RLFK Return Line Fitting Kit
1 Installation Manual 206-1-0453
1 AirDog®- with Serial Number Plate
FPII-200-LP
1 Wiring Harness with Indicator Light 5E-2-010
1 Fuel Filter Monitor Light Plate 201-3-0004-S
1 7 ft. Section DOT Air/Vapor Return Line 4C-1-02-05-010-7FT
2 #10 M JIC x 1/2” M NPT Straight Adapter 4A-1-01-10-08-S
2 #10 F Swivel x #10 M JIC 90° Elbow 4A-2-04-10-10-S
1 #6 M JIC x 1/4” M NPT Straight Adapter 4A-1-01-A-C-SZ
1 Grommet 5J-1-1-04-2758
908-08-0800 AirDog®FPII Basic Fitting Kit
Fuel Filter FF200-MG-6
Water Separator WS200-WS
QTY Description Part Number Image
908-00-0304 Frame Mount Kit
2 Mounting Bracket 002-3C-0003
002-3C-0004
1 901-08-0100 Hardware Kit, Includes:
4 ea 3/8” x 1-1/4” Hex Head Bolts 1J-1-C20SZ
4 ea 3/8” Nuts 1S-1-CSZ
4 ea 3/8” Lock Washers 1R-6-CSZ
4 ea 1/4-20 x 2” SHC Screws 1L-A32C
4 ea 1/4” Lock Washers 1R-6-AC
4 ea 1/4-20 Hex Nuts 1S-1-AC
1 Fuel Pressure Sensor 5 psi 908-5C-9-007
ADFK-453 Installation Kit
SBK-1000 Sandwich Bracket Kit
1 901-08-0100-SB Hardware Kit, Includes:
3 ea 3/8”-16 x 3-1/2” Hex Head Bolts 1J-1-C56SZ
7 ea 3/8” Nuts 1S-1-CSZ
7 ea 3/8” Lock Washers 1R-6-CSZ
1 Sandwich Mounting Bracket Kit for AirDog®& Champ 002-3C-0010-SBF
Includes: 1 Front - 1 Back & 002-3C-0011-SBB
1 Center Bracket 002-3C-0006PCB
OPTIONAL

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 4 Selecting the Best Mounting Location
Selecting the Best Location to Mount the AirDog®
Installing the AirDog® at the proper location on the vehicle is most important. When deciding where
to locate the AirDog®, the following points should be considered:
• Protection from the elements and road debris
• Accessibility for service
CAUTION: DO NOT mount the AirDog®directly on the engine. Mounting the AirDog®
directly on the engine will immediately VOID your AirDog® Warranty!
NOTE: On various class 8 trucks, the manufacturer may use other than traditional steel braid fuel
lines. These lines require special ttings. The ttings used with the original primary fuel lter are
specic to the fuel lines used on the truck. When possible, mount the AirDog®in the location that
will allow the use of the original fuel lines and ttings.
The following examples, Figures 2 thru 5, show dierent AirDog® installations. There are many
variations in the arrangements and the components on the various trucks. With a little ingenuity, the
AirDog® can be successfully installed on any class 8 truck.
Figure 2 shows the original fuel lter mounted on a bracket to the rear of the engine
compartment and just above the frame behind the steering column.
Figure 2
Figure 3
Figure 3 shows the primary fuel lter mounted on the frame.
In Figure 4, the AirDog® is mounted on the original fuel lter bracket high above the frame
and toward the front of the engine compartment.
Figure 4
Figure 5
The installation in gure 5 shows the AirDog®mounted on the frame on the passengers side, up
front by the radiator.

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 5 Mounting the AirDog®
Section 5: Mounting AirDog® on the Truck’s Frame (Drilling Method)
NOTE: Do Not mount the AirDog® on the engine! Mounting the AirDog®on the engine will
immediately void the AirDog® warranty. Mount the AirDog® on the truck frame.
5A-1. Remove the original primary fuel lter from the vehicle.
Figure 6
Figure 7
5A-2. Hold the AirDog® with the brackets and lters attached next to the frame.
5A-3. Turn the steering wheel fully to the left and to the right to check for tire clearance.
Figure 8
Figure 9
5A-4. Mark and center punch each hole location.
5A-5. Drill a 3/8” hole at each of the 4 previously marked locations.
WARNING! USE CARE NOT TO DRILL INTO OR DAMAGE ANY WIRING, AIR LINES
OR OTHER COMPONENTS LOCATED BEHIND THE FRAME RAIL.
Figure 10 Figure 11
5A-6. Loose assemble the mounting brackets and AirDog® to the frame. After mounting the
AirDog® on the brackets, snug the fasteners to achieve a good relaxed t, then nish tightening all of
the fasteners.

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 5 Mounting Brackets
Sandwich bracket comes with all hardware that is needed and NO DRILLING
Sandwich bracket can be used in any combination of ways to t your truck.
Sandwich bracket slides right
over existing frame.
OPTIONAL KIT AVAILABLE (PN: SBK-1000)
NO DRILL Universal Sandwich Mounting Bracket

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 5 Mounting the AirDog®
Mounting the AirDog® on the original lter bracket
5B-1. Remove the original fuel lter from the mounting bracket (Figure 13).
Figure 12 Figure 13
5B-2. Attach the AirDog® mounting brackets to the original lter plate. If the original bracket is not
wide enough to t the AirDog® brackets, bolt a plate to the bracket.
Figure 14 Figure 15
5B-3. Loosely assemble the brackets to the plate and the AirDog® to the brackets.
5B-4. After mounting the AirDog® on the brackets, snug the fasteners to achieve a good relaxed t,
nish tightening all of the fasteners.
NOTE: These steps are necessary to prevent stress cracks from forming in the mounting brackets
due to vibration.
Assembly Instruction for Hose Barb
1. Cut hose line to length.
2. Apply oil to tting.
3. Push tting into line until seated.

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AirDog®FPII-200 Cummins®ISX15 & X15
Figure 17
Figure 16
Section 6 Fuel Fittings, Pressure Sensor & Lines
FUEL LINE OVERVIEW
The AirDog® has been engineered to eliminate fuel related problems. It is important that the fuel
lines are assembled and installed properly so as not to cause fuel ow restriction.
When possible, use the fuel lines that are on the vehicle. This will reduce your installation costs and
make the installation go much more quickly.
NOTE: On various class 8 trucks, the manufacturer may use other than traditional steel braid fuel
lines. These lines require special ttings. The ttings used with the original primary fuel lter are
specic to the fuel lines used on the truck. When necessary and /or possible, utilize the OE ttings
from the original fuel lter head. Always inspect the original fuel lines for size, length, and condi-
tion. If the fuel lines are in good condition and the correct size and length to adequately reach the
AirDog®, you may want to go ahead and use them. If any of the fuel lines need to be replaced, it is
recommended that the fuel lines selected meet or exceed DOT requirements.
Fuel Supply Line: The fuel supply lines from the tank to the AirDog®and to the engine should be
size 10 or, at the absolute minimum, size 8 (1/2” ID).
Air/Vapor Return Line: The AirDog® Air/Vapor return line can be connected to the engine’s return
line. A size 6 is adequate for the Air/Vapor return line.
Primary Fuel Filters: It is most important that there are no fuel lters between the fuel tank and the
AirDog®or between the AirDog® and the engine’s transfer pump to plug and cause restriction. These
lters should be removed from the system as part of the AirDog® installation.
Secondary Fuel Filters: DO NOT REMOVE SECONDARY FUEL FILTERS. This is the lter
between the transfer pump and the engine.
Section 6A: Installing the Fuel Fittings and
Low Fuel Pressure Sensor
NOTE: Figures 16 & 17 illustrate the installation of straight ttings. In some instances 90º ttings
may be required to connect the fuel lines to the AirDog®. Therefore, for your convenience two extra
90º ttings have been included in the kit.
6A-1. Install the straight #10 JIC x ½” NPT fuel tting in the AirDog®fuel port marked “EN-
GINE”. Use the 90º swivel ttings as needed when connecting the lines.
6A-2. Install a straight #10 JIC x ½” NPT fuel tting into the fuel inlet port next to the regulator
marked “FUEL IN”. Use the 90º swivel ttings as needed.

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AirDog®FPII-200 Cummins®ISX15 & X15
Figure 19
Section 6 Fuel Lines
Section 6A: Installing the Fuel Fittings and Pressure Sensor, cont’d
6A-3. Install the ¼” NPT x #6 JIC Male Air/Vapor return tting into the Air/Vapor return port
marked “TANK”.
Figure 18
6A-4. Remove the 1/8” NPT plug from the end of the pre-installed 45° tting in the AirDog® base.
Install the fuel pressure sensor into the 45° elbow.
SECTION 6B: Installing the AirDog®Return Line
The AirDog® returns entrained air & vapor to the fuel tank. The AirDog® Air/Vapor return line may
be connected directly to the engine fuel return line.
The AirDog® SPECIAL ISX15/X15 RETURN FITTING must be used for Installation!
6B-1. Disconnect the engine fuel return line from the #8 JIC are tting located on the side of the
engine and remove the tting. It is necessary to temporarily remove the adjacent banjo tting as
shown in gure 21, to install the ISX Special Return tting.
Figure20
Figure 21
6B-2. Install the 16 mm ORB Male x 16 mm ORB Female x #6 JIC tting, with the air/vapor return
port, into the engine ‘fuel return port’.
6B-3. Install the 1/8” NPT X #6 JIC tting in the port of the ISX15/X15 Return Fitting. Index and
lock down the return tting. Re-install the adjacent banjo tting.
Figure 22
Figure 23
6B-4. Re-install the original return tting into the new AirDog®ISX15/X15 Return Fitting and
re-connect the engine fuel return line.

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 6 Fuel Lines
SECTION 6B: Installing the AirDog®Return Line
6B-5. Measure and cut a length of fuel line necessary to reach from the Air/Vapor return tting on
the AirDog® to the Special ISX Return Fitting on the engine.
AirDog®Special ISX/X15 Return Fitting
Figure 27
Figure 28
Figure 24 Figure 25
6B-6. Assemble the fuel line with the proper end ttings for the connections.
NOTE: This assembled fuel line is for illustration
only. Use the proper end ttings that apply to your
application!
6B-7. Route and connect the Air/Vapor return line to the proper ttings
on the AirDog® and the return tting. Properly tighten the ttings. Secure the fuel line as necessary
to prevent abrasion and chang.
Connecting the AirDog®to the Engine and Tank
6C-1. Connect the fuel line to the engine, which was connected to the original fuel lter, to the
tting in the AirDog®out to “ENGINE” port.
Figure 26
OR

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 6 Fuel Lines
SECTION 6C: Connecting the AirDog® to the Engine & Tank, cont’d
6C-2. Connect the fuel line from the tank to the tting in the AirDog®“FUEL IN” port.
Figure 29 Figure 30
Connecting the AirDog®to the Engine and Tank on vehicles with plastic fuel lines
6C-3. Remove the ttings for the plastic lines from the original lter assemblies and install them in
their respective inlet and outlet ports in the AirDog®.
6C-4. Connect the fuel line to the engine to the AirDog® fuel outlet tting.
Figure 31
FUEL LINE from AirDog®TO ENGINE
6C-5. Connect the fuel line from the tank to the AirDog® fuel inlet tting.
Figure 32
FUEL LINE from TANK to AirDog®

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 7 Wiring Harness
WIRING HARNESS
*VERY IMPORTANT: The AirDog®wiring harness requires a 15 amp fuse.
The AirDog®wiring harness has a low pressure sensor and an amber LED indicator light as standard
equipment. The indicator light will illuminate at start-up, remain on for a few seconds, then go o
and should remain o unless pressure ow to the engine drops below minimum requirements.
THE AIRDOG®WIRING HARNESS
Securing the AirDog®Wiring Harness Relay to the Vehicle
7-1. Secure the AirDog® wiring harness relay to the vehicle.
This picture shows the relay mounted on the rewall.
7-2. Route the AirDog®wiring harness pump motor lead and the fuel pressure sensor lead to the
AirDog® unit. Connect the wiring harness pump motor lead to the AirDog® unit pump motor lead.
7-3. Connect the AirDog® wiring harness fuel pressure sensor lead (lead with the green seal) to the
AirDog®Pump Motor Lead (7-2)
Fuel Pressure Sensor Lead (7-3)
Indicator Light (7-5 & 7-9)
Battery Positive Lead - Red (7-11)
Battery Negative Lead - Green (7-11)
Indicator Light Lead (7-5 & 7-9)
Relay Trigger Lead (No Connector/Plug) (7-5 & 7-6)
Relay
(7-1)

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 7 Wiring Harness
Relay Trigger Lead and Indicator Light Lead
The AirDog® Wiring Harness Indicator Light lead must be routed through the rewall and
to the dash board. The Relay Trigger Lead must be connected to a contact point that is
electrically “HOT” when the key is in the “RUN” position. This could be either in a spare fuse
holder in the fuse panel or on the ignition switch itself.
Note: DO NOT connect the AirDog®wiring harness relay trigger lead to a point that is
“HOT” when the key is in the ACCESSORY position.
7-5. Route the AirDog®wiring harness trigger lead (red wire with no connector/plug) and indicator
light lead through the rewall.
Routing the Indicator Light and Relay Trigger Lead through the rewall:
7-4. Most Peterbilts and Kenworths have access holes located below the steering column. Remove
the plug and route the leads through the hole. For other make trucks, drill a 5/8” hole in rewall to
allow entry of the indicator light lead into the cab. Use the grommet to seal around the loom cover.
By the Steering Column Under the Dash
NOTE: Be sure to seal the opening or install a grommet around the wire loom to prevent water
leakage and protection from chang.

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 7 Wiring Harness
Battery
Ignition Accessory
DO NOT
Connect Here
Relay Trigger Lead and Indicator Light Lead, cont’d
7-6. Connect the red relay trigger lead to a terminal on the ignition switch that is “HOT” when the
ignition key is in the “RUN” position OR connect the red relay trigger lead to a fuse holder in the
fuse panel that is “HOT” when the ignition key is in the “RUN” position.
THIS OR THIS
INSTALLING THE AIRDOG®WIRING HARNESS INDICATOR LIGHT
Amber LED Indicator Light
7-7. Select a location on the dash that is easily visible to the driver. Remove the dash components as
necessary to access the area behind the selected location.

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 7 Wiring Harness
7-8. Drill a 9/16” hole in the dash at the selected location. Be very careful when drilling. Do not
damage components located behind the dash.
7-9. Remove backing from the double-sided tape on backside of the AirDog®wiring harness
indicator light dash plate. Install the dash plate and indicator light in the dash. Connect the AirDog®
wiring harness indicator light lead to the connector on the wiring harness.
7-10. Re-assemble the dash components back to their original position.
Installing the Indicator Light, Cont’d
CONNECTING THE POWER SUPPLY LEADS
The power supply leads can be easily connected to the appropriate contacts on the alternator.
Any high amperage terminal that is always “HOT” is OK for the Positive + (RED) lead. Be
sure the NEGATIVE - (GREEN) lead is connected to a reliable chassis ground.
7-11. Route the red & green power leads to the alternator. Connect the green (-) ground lead to the
alternator Ground connection.
7-12. Connect the red (+) positive lead to
the alternator Hot Lead going to the battery.

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PureFlow®Technologies Inc.
AirDog®FPII-200 Cummins®ISX15 & X15
Section 8 Initial Start Up
SECTION 8: INITIAL START UP PROCEDURE
The AirDog® is a self priming system. However, to prevent damage to a dry seal and reduce the life
expectancy of the system, it is suggested to pre-ll the water separator/pre-lter with diesel fuel to
the bottom of the “NUT PLATE”.
r 8-1. Rub CLEAN diesel fuel or oil on lter seals before installing to ensure a proper seal.
r 8-2. Pre-ll the water separator/pre-lter with diesel fuel up to the bottom of the nut plate.
r 8-3. Turn the starter key to the on/run position.
r 8-4. The AirDog®should now be running and pumping fuel, bleed the fuel line to the engine by
loosening the fuel line connection at the engine tting. As soon as the line is purged of air
and pure fuel is observed, properly tighten the fuel tting.
NOTE: Put a rag or shop towel over and around the tting to prevent fuel splatter or
spray. Catch all spilled fuel and dispose of properly. Wear safety glasses.
r 8-5. Start the engine.
RECHECK ALL FUEL FITTINGS FOR LEAKAGE AND PROPER TORQUE.
BE SURE ALL FUEL LINES ARE PROPERLY ROUTED TO PROTECT
FROM EXCESSIVE HEAT AND SECURED TO PROTECT FROM CHAFING
AND ABRASION. RECHECK ALL ELECTRICAL LINES, SECURE AS
NECESSARY.

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AirDog®FPII-200 Cummins®ISX15 & X15
Section 9 Filter Service
Servicing the AirDog®Fuel Filter and Water Separator/Pre-Filter
The AirDog® low pressure sensor monitors the fuel lter and water separator.
FUEL FILTER: When the fuel lter becomes plugged, the AirDog® Indicator Light will illuminate,
indicating it is time for a fuel lter replacement. The AirDog® fuel lters have a typical lifespan of 25,000+
miles, and up to 40,000 miles, as they are made with a high-quality and high-capacity Micro-glass media, as
opposed to a paper element, and lter life is aected by many variables. In any case, we do not recommend
exceeding 40,000 miles of service with a fuel lter. It is recommended that you keep a replacement AirDog®
fuel lter on-hand, ready for replacement when the AirDog® Indicator Light illuminates. When replacing
the fuel lter, be sure to clean the under side of the AirDog® base. Rub clean diesel fuel or oil on lter seals
before installing to ensure a proper seal. It is not necessary to pre-ll the fuel lter with fuel, the AirDog®
will ll the lter and prime the system automatically. Follow the instructions on the lter for proper tightening
procedures.
The Water Separator/Pre-Filter
WATER SEPARATOR: Should the water separator/pre-lter or the wire screen in the nipple become
plugged, preventing sucient operating pressure ow to the engine, the Indicator Light will immediately
illuminate.
Check the water separator/pre-lter for plugging. Clean or replace as necessary. If the light continues to be on,
check the screen in the water separator/pre-lter nipple for debris and plugging. Clean as necessary.
Replace the water separator if it becomes damaged or permanently plugged. Servicing of the water separator
simply requires draining at regular intervals. It is suggested to check/drain the water separator weekly or as
needed should you experience excessive ‘water in fuel’ conditions. Before re-installing the water separator
after cleaning, be sure to clean the under side of the AirDog® base. Rub clean diesel fuel or oil on lter seals
before installing to ensure a proper seal. Follow the instructions printed on the water separator/pre-lter for
proper tightening procedures.
When tightening lters with a lter wrench, DO NOT overtighten as doing so may damage the lter.
Caution: Be careful to prevent any contaminants from entering the water separator when removing
for cleaning or replacement. Although the water separator pre-lter nipple has a protective
wire screen, any debris passing through the system could cause the gerotor to lock up, which
can then cause the in-line fuse to blow. Such a pump lock-up is not covered under warranty.
Dispose of waste fuel and used lters properly to protect our environment.
AirDog®
Fuel Filter Pre-Filter Nipple
with Wire Screen
(1-1/8th Inch Hex)
Pre-Filter/Water Separator
with Drain Valve