CJ-7 Projects


Lightforce Lights - H.I.D. High-intensity discharge Upgrade

HEI Ignition System (GM Style) Installed in the AMC 360 V8
Getting rid of gremlins and improving performance

Installing 23,000 Volt Offroad Lights

Autogage Tachometer Installation

 Home Page
 Photo Album
 Product Reviews
 Cool Products
 Tech Section
 Readers Rigs
 4x4 Club Links
 Links Directory
 Shop Offroaders
 Centralia PA
Project CJ-7
Offroaders Guide
to Gearing up
for Offroad

From Basic Equipment to Well Equipped.  An extensive list guide to help you prepare your vehicle for the offroad.


Onboard Air
Converting a York
AC Compressor
to Pump Air

Trailering Safety and Trailer Hitch Information


Off-Road Truck Driving Techniques and Safety

Off-Road Lights
by LightForce Product Review / Installation.
from Off-Road Lights


Jeep Dana 300 TeraLow - 4:1 Gearset for the Dana 300 Transfer Case

AMC V8 Engines
GEN-1 Nash/Hudson/Rambler V-8s (1956-1966) through to the GEN-3 AMC Tall-deck (1970-1991)

Chevy Small-Block V8 Engines
Chevy Small-Block V8 Engines Manufactured by General Motors - Production: 1955?2002

Hemi Engine - All about the Hemi Engine

Ford Engines
4 Cylinder, 6 Cylinder, 8 Cylinder, 10 Cylinder, 12 Cylinder Ford Engines

Ford V8 Engines
8 Cylinder Engines manufactured by Ford

Ford 351 Cleveland V8 Engines
351 cubic inch V8 Engines manufactured by Ford

Chrysler Hemi Engine

AMC V8 hp/Torque, Compression & Bore/Stroke by year

Engine Size Conversion Table
Converting engine displacement from CID, Liters, C.C.

Engine Overheating Basics - 16 Common Causes of an Overheated Engine

Fan Clutch Diagnosis
How to tell if the Fan Clutch in your Cooling System is failing or has failed.

Automotive Gauges & Instrument Functions
Information they display & their importance.


From the
Department of Cheap   Tricks and Useful Tips

Ultra-Cool Hand Throttle for Free!

Jeep V8 Swap Tips

The Exploding Clutch

Radiator Protection using 6 bucks worth of material

Cracked Under Pressure - Fixing a smashed fingernail

A Cheap, effective alternative to undercoating

Home-built Saginaw Gearbox Brace for the cost of lunch!

Ammo Box Storage - Mounting Them for Quick Disconnect

Home-built Serious Skid-Plate protection for the Oil Pan for under 20 bucks!

Ramp Travel Index
RTI / Ramp Travel Index  What it is and how to calculate it, with and without the ramp.





Project Jeep CJ-7
Onboard Air
York AC Compressor Conversion

Back to Project Index


Dcp_5160.jpg (45898 bytes)

York AC Compressor Conversion

A picture is worth a thousand words so we'll start off with a diagram.  This is essentially what my system looks like.  Below the diagram is an identification chart of the components and where I got them.  It also shows how I connected the components and in what order they were assembled across the manifold.

1 York AC Compressor (factory installed on an AMC 360 out of a Jeep Grand Cherokee)
2 Tube-O fitting to 1/2" NPT (Kilby's Rotolock fittings, )
3 1/2" NPT female to female (kilby or a hardware store)
4 Air Intake Filter (Kilby Air Intake Filter, FS-07-050)
5 Square D pressure switch (set to 120 psi off) (Kilby, 49J59)
6 Air Manifold (hardware store)
7 Adjustable Relief Valve (set to blow at about 130 psi) (kilby, NC25)
8 Pressure Gauges (on at manifold, one on dash) (hardware store)
9 Oil / moisture trap (Coalescing Filter)
10  Check Valve (Kilby, CB38)
11  1/4" T, 3 female ports (hardware store)
12  1/4" Couplers, male port (hardware store)
13  Barbed 1/4" to 1/4" male port (hardware store)
14  1/2" NPT male to 1/4" barbed hose fitting (hardware store)
15  1/4" male to 3/8" (the Oil / moisture trap is actually a 3/8" so the fitting on both sides of the moisture trap is a 1/4" male to 3/8" male.  (hardware store)
16  1/4" Elbow, male one side, female other side. (hardware store)
17  Male to Male connector (hardware store)
18  1/4" Elbow, male one side, female other side. (hardware store)
19 1/4" NPT to 3/8" Nylon Quick Connect (Grainger) NOTE: The air horn and pressure gauges use different sizes, pressure gauges use 1/8" Nylon Quick Connect and Air horn fitting use 3/8" Nylon Quick Connect.
20  1/4" male NPT to 1/8" female NPT (hardware store)
21  3/8" Nylon Quick Connect to 1/8" male NPT (air horn adaptor) (hardware store)
22  Yard Sale acquisition - Really loud air horn off a '76 Mack
23  1/8" nylon air hose  (hardware store)
24  Stock 1/4" air line with male factory fittings  (hardware store)
25  Air Tanks, Custom Front and Rear Bumper Project
26  1/4" NPT male to male  (hardware store)
27 Air Blow Gun — 1/4"  female Inlet, 1/4" threaded outlet. 
28 3/8" nylon air hose for air horn (needed volume)  (hardware store)


As I stated earlier, the York 210 was already on my AMC 360 engine when I bought the engine so I had the brackets to mount it to the engine.  Originally the York was oriented with the inlet and outlet facing the passenger side.  I had to rotate the York so that the inlet and outlet were oriented at the top of the compressor, rather than on the side of the compressor.  The reason for this is so that less oil is blown out the outlet during operation.  The York compressor made the rotation easy by having a square bolt pattern, allowing it to be clocked 90 degrees on the factory brackets.   The pulley is not affected by the rotation due to its centered position.  Rotation also allows easy access to the oil fill plug located on the side of the compressor housing. Dcp_5160.jpg (45898 bytes)


Before rotation 


Before rotating and mounting it permanently, I needed to first, clean it up and test the clutch.  I gave it a good cleaning with degreaser and drained the old oil.  Then I gave it a paint job with a color resembling cast aluminum for that clean OEM look. 

Testing the Compressor Clutch

The York clutch is just an electro-magnet and can be tested easily.  If you test it on the vehicle, do so with the engine not running.  Remove the belts to the York.  The pulley on the York should spin freely and easily.  If not, its seized and may need to be cleaned up or replaced. Apply 12 volts to the single wire coming off of the pulley clutch (the housing mounted to the engine provides the ground if the battery is in the vehicle).  The clutch should "engage" the pulley and no longer spin freely, rather turning the pulley should rotate the pistons with the York.  If you are bench testing the clutch, clamp the negative end of 12 volts to the housing and the positive end of 12 volts to the single clutch wire.  My clutch worked fine.  I still removed it and cleaned it up.  Don't paint the inside area of the clutch.  

Further York Identification Information can be found here.

York Maintenance Information

Mounting Options

With the York oriented so that the inlet and outlet are at the top, I was focused on modifying the inlet and outlet ports.  Even though the stock AMC freon fittings were low profile, finding the right adapters to convert it to NPT type fittings was not easy at my local hardware stores.  I'm sure there are parts out there, probably a good place to look would be in a Granger catalog.  However instead of wasting too much time looking, I ordered a pair of Custom Rotolock fittings from Kilby Enterprises, part# 44760, that convert the compressors inlet and outlet to 1/2" NPT.   These adapters can be used on Tube-O compressors with drop-in adapters and come with adapters, teflon seals and Tube-O o-rings.  Cost for the pair was $25.   Also part of the Kilby order was an inlet filter

On the Inlet side, I used:

  • Tube-O fitting to 1/2" NPT (Kilby's Rotolock, part# 44760)
  • Air Intake Filter (Kilby, Part# FS-07-050) 
  • 1/2" NPT female to female, which apparently is also supplied by Kilby with the Air Intake Filter.  When I bought the filter, the this wasn't supplied.

kilby-intake-filter.jpg (9023 bytes)

Dcp_5158.jpg (31753 bytes)


On the outlet side, I used:
  • Tube-O fitting to 1/2" NPT (Kilby's Rotolock, part# 44760)
  • 1/2" NPT female to female
  • 1/2" NPT male to 1/4" barbed fitting (note: I might swap this out for a 1/2" NPT male to 3/8" barbed fitting and use 3/8 air lines instead.  This is  because the compressed air is moving so fast and the hose is small, the air heats up the hose, thus fatiguing it pre-maturely or blowing it off the 1/4" barbed fitting making a hell of a noise.)

The position I oriented the inlet and outlet in (picture to the right) seemed to be the best for clearance reasons and the direction I wanted the outlet hose to go. 

Dcp_5164.jpg (28387 bytes)
Assembling the Array

Dcp_5154.jpg (39789 bytes)Next up was to assemble an array of NPT components.  As you can see in the picture to the right, the Air Manifold came in handy to attach all these components in a clean, organized manner.  When assembled into this unit, mounting them became easier since it was one solid piece rather than several smaller pieces.  These components were to accomplish the following things.  

  • Remove oil and moisture from the compressed air using the oil / moisture trap.
  • Stop the backflow of air into the compressor using a check valve.
  • Regulate the power to the compressors electric clutch to control the air pressure using a Square D pressure switch.
  • Attach a Relief Valve to open at a pre-set pressure to prevent damage or an explosive blowout due to pressure switch or clutch disengagement failure.
  • Branch off air to several locations, to the front bumper (air tank), to the rear bumper (air tank), to the in cab air pressure gauge, and to my optional air horn.
  • I also attached a 1/4" Coupler and an under the hood air pressure gauge.

Dcp_5155.jpg (30227 bytes)When assembling these components as shown, I took note of how much space I had to work with in the area I was mounting these components.  My location of choice was hanging from the grill brace in my Jeep.  I test fit all the components first, checked the fit in its final location.  It fit good so I then used thread tape (the white stuff in small rolls) to seal every connection. 


Installing the Array 

With the array of NPT components assembled, it was time to mount them in the engine bay.  I didn't want to mount them to the fender for the reason that if I ever wanted to remove the fender to work on the engine, I wouldn't have to remove anything other than the fender.  Thus my fenders have very little attached to them for easy removal.

The best place I could find to mount the air array was to hang it from the grill brace that runs from the firewall to the grill on the passenger side.  This area was wide open and could accommodate the array of air components.

Creating the Hanging Brackets

Through a source of free scrap metal (dumpster at a metal shop) I acquired a few lengths of galvanized angled steel.  Using this steel I created some simple hangers that clamped down on the air manifold on one side and hose clamped to the oil / moisture trap on the other side.  See pictures.

 100_3925.jpg (29090 bytes)

Creating the hangers was simple.  To hang the Array from the grill brace I created two longer hangers and 2 short clamps using a the galvanized angled steel and drilling two holes at the top of the long pieces and two holes on the short pieces.  I then ran two 1/4" grade 8 bolts through the two halves of each brace to clamp down on the grill brace.  I had wrapped electrical tape around the grill brace so it could help prevent the clamp from spinning on the grill brace. (See pictures to the right).  

At the bottom of the rear hanger, I did the same thing with a short piece of the same angled steel and clamped it onto the air manifold.  At the front, I cut a slit on the angled hanger and ran a hose clamp through the slit and around the oil / moisture trap.

100_3934.jpg (47256 bytes)

100_3934b.jpg (32021 bytes)

Dcp_5165.jpg (49896 bytes)

100_3926.jpg (48416 bytes)

100_3937.jpg (50252 bytes)

100_3938.jpg (60971 bytes)

Dcp_5166.jpg (46075 bytes)

100_3932.jpg (90754 bytes)

Overview after air horn install


Routing the Air Lines

York compressor outlet to Array

 I mounted the array of NPT components so that the inlet side was oriented towards the outlet side of the York compressor.  This allowed me to run a short line from the York to the inlet side of the oil / moisture trap.  Starting from the York outlet, the parts used to do this were: 

  • Kilby's Rotolock (Outlet side)
  • 1/2" NPT female to female
  • 1/2" NPT male to 1/4" barbed fitting
  • Stock air hose, cut ends
  • Barbed 1/4" to 1/4" male port
  • 1/4" female to 1/4" male elbow
  • 1/4" female to 3/8" male adapter


To the Tanks
The air hose was an "off the shelf" stock 25' air hose with 1/4" NPT male fittings on either endI cut the 25' hose in half and used the stock fittings at the bumper ends.

When you look at the base of the blue air manifold, you'll see a 1/4" NPT "T" fitting with two barbed fittings facing in either direction.  These were for routing air to the front bumper and to the rear bumper.  

Where the hose entered the bumpers, I was going to locate quick disconnects so I could get a supply of compressed air at these locations.  So at the bumpers, I used 4 NPT components to "T" in three directions, to the Quick Disconnect, to the Bumper (air tank) and back to the air  manifold under the hood.  I had used a 1/4" NPT tap to tap threads into the 1/4" steel bumpers.  I located the inlet into the bumper air tank behind the bumper (facing the Jeep) so it was out of harms way.  The parts I used at the bumpers were: 

  • 1/4" male to 1/4" female elbow
  • 1/4" male quick disconnect
  • 1/4" "T" with female fittings
  • 1/4" male to male adapter (into the threaded bumper and "T")

The air lines were routed along the frame rail on the passenger side.

100_3931.jpg (33768 bytes)

100_3935.jpg (36680 bytes)

Dcp_5154.jpg (39789 bytes)

100_3949.jpg (63652 bytes)

Air quick disconnect with "T" into the bumper. Same on rear bumper.

Dcp_5169.jpg (18334 bytes)

Dcp_5353.jpg (11097 bytes)

Air line to the rear bumper


To the In-Cab Air Gauge

Using 1/8" Nylon (or plastic) tube and 5/32 Press-To-Lock (or Press-in) fittings, a line was run from the air manifold, through the firewall and to an air gauge that was mounted under the dash board.  This was mainly so I could monitor air pressure from in the cab without opening the hood.

100_3941.jpg (19927 bytes)

Electrical requirements for this onboard air system is minimal.  The only component that requires power is the York's clutch, which is basically just a magnet that engages the pulley to the York shaft.  The cutch has a single black wire that needs 12 volt to engage the clutch.

You don't want to supply power straight from a switch to the York.  That would require you to monitor the pressure and turn it off before you blow up your system.  Instead you want to leave that job up to a Pressure Switch.  Pressure Switches are common and can be bought from many suppliers.  Kilby Enterprises sells a Square D for $23.

The Square D pressure switch (49J59) is factory pre-set to cut-in at 135 
psi and cut-out at 175 psi.  You don't want to run pressures that high, mainly because of the stress it'll put on the York.   The cut-out pressure is adjustable so I adjusted my Square D to cut out at 120 PSI. The Square D has a 1/4" male NPT port.  For adjustment to the pressure switch, see the manufacturers instructions.  Along with adjusting the the pressure switch, you will want to adjust the pressure Relief valve to just above the cut-off pressure of the pressure switch. 

The Square D Pressure Switch has two Electrical circuits.  The circuits makes contact when the pressure drops below the lower air pressure limit, and disconnects when the air pressure reaches the upper limit.  For this application, you only need to use one of the two circuits.  Hookup to the York is a matter of running your 12 volt power line into the Square D pressure switch to one of the two circuits and then off of the same circuit run a power line out to York's clutch power line.

100_3939.jpg (57371 bytes)

100_3940.jpg (52506 bytes)


100_3950.jpg (37167 bytes)



Note:  Do not run your power line directly from a 12 volt power source such as the battery into the pressure switch.  Instead, run the 12 volt line first through a 20 amp fuse and then through a 12 volt, 30 amp minimum rated power switch.  Install the power switch somewhere easily accessible such as on the dash of the vehicle so that you can control when you want air.  I used a flip cover switch and installed it where my Jeep's radio would have been along with several other power switches.  I also wired in a bright blue LED to let me know when the power is on.



The Air Horn!   :-)

When you have air, you gotta get one of these.  I paid 8 bucks for it at a flea market.  Hooking it up was relatively easy after the air system was installed. Finding a place to put it was the hardest thing to do.  

I figured out the I could mount it right next to the array of NPT components under the hood and bolt it to the rear hanger.  I had to run a 1/4" air line (I used nylon air lines and Press-To-Lock)  to it since 1/8" didn't supply enough air for a good blast.  To control air flow, I used the push button part of an air gun and replace the inlet and outlet with threaded elbows.  I "temporarily" taped it to my steering column 2 years ago (I gotta clean that up).  

100_3954.jpg (32812 bytes)

100_3932.jpg (90754 bytes)


100_3952.jpg (43093 bytes)


100_3955.jpg (57003 bytes)




Project Jeep CJ-7 
Onboard Air
York AC Compressor Conversion

Back to the
Project Index




Offroad Tire Info
Tire Terminology
Wheel Terminology
How to Pick the Right
Tires for your Truck
Truck Tire Info
Tires - What Hits What Fits
All Terrain  Mud Terrain
Tire Reviews & Info
Mud Terrain MT Tire Reviews
All Terrain AT Tire Reviews
Super Swamper Bogger
Super Swamper SSR
Super Swamper SX
Super Swamper Vortrac
Interco IROK TSL
Super Swamper LTB
Super Swamper TSL
Super Swamper TSL Radial
Super Swamper Narrow
Interco SS-M16 Swamper
Thornbird TSl Radial
Thornbird TSl Bias
Thornbird TSL
Parnelli Jone Dirt Grip
BFGoodrich Krawler
BFGoodrich MT T/A KM
BFGoodrich MT T/A KM2
BFGoodrich AT TA KO
BFGoodrich Mud King XT
Bridgestone Dueler MT
Cooper Discoverer ST
Cooper Discoverer STT
Cooper Discoverer ST/C
Firestone Destination MT
General Grabber MT
General Grabber AT2
Green Diamond Icelander
Ground Hawg Mud Tire
Hankook Dynapro MT
Hankook Dynamic MT RT01
Hercules Terra Trac MT
Hercules Trail Digger MT
Kelly-Springfield Safari DTR
Kelly-Springfield Safari MSR
Kumho Road Venture MT
Kumho Road Venture KL71
Kumho Road Venture AT
Dick Cepek Mud Country
Dick Cepek F-C II
Dick Cepek Fun Country II
Dick Cepek Fun Country Nylon
Dick Cepek Fun Country Kevlar
Mastercraft Courser MT
Mastercraft Courser HTR
Mastercraft Courser HTR Plus
Maxxis BigHorn Radial
Maxxis Creepy Crawler
Maxxis Trepador
Maxxis Buckshot Mudder
Maxxis MA-SW
Maxxis M-8080 Mudzilla
Maxxis MT-754 Buckshot
Maxxis MT-753 Bravo
Maxxis MA-751 Bravo
Maxxis MA-S2 Marauder II
Maxxis MA-S1 Marauder
Maxxis MT-762 BigHorn
Nitto Mud Grappler
Nitto Dune Grappler
Nokian Vatiiva MT
Pit Bull Rocker Extreme
Pit Bull Maddog
Pit Bull Growler
Goodyear Wrangler MT/R
Pro Comp Xterrain
Pro Comp All Terrain
Pro Comp Mud Terrain
Pro Comp Xtreme AT
Pro Comp Xtreme MT
Toyo Open Country MT
TrXus Mud Terrain
TrXus STS All Terrain
Mickey Thompson MTZ
Mickey Thompson MTX
Mickey Thompson Baja Claw
Mickey Thompson Baja Crusher
Competition Claw
Dunlop Mud Rover
Yokohama Geolandar

Latest trips Offroad
... trail reports with the Project CJ-7
click here.

Sounds System, Raised the Rear Seat
Storage below and a great place to mount 6x9 Speakers for Great Bass ... In a Jeep!

York AC Compressor Conversion.  What used to pump Freon, now pumps compressed air to the front and rear bumpers.  125 psi,  2 gallons of storage, air fittings at the bumpers, enough CFM to power air tools!.  Click Here for more  Details


Dick Cepek's 2008 F-250 Super Duty Project Vehicle ? Project CRUSHER

Warn X8000i
Winch Installation

ARB Air Locker Install
Jeep Wide Track Axles Swap

Mud Tire Reviews

Building a Garage?
Need a Garage Plan?

Reader's Rigs and Seriously Stucks!


Jeep Trans Swap Info
T-18A Transmission Rebuild & Short Shaft Conversion