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Onboard Air Setup #3 (YJ Wrangler 2.5L)

If you have ever wheeled far away from civilization and are looking for a very handy mod, On Board Air is it!

You Can

  • Run Air Tools (almost constantly) to fix trail breaks
  • Fill Tires (Fast)
  • Clean Dirty Parts
  • Fill inflatable toys and or mattresses

It is a very hand thing to have on your jeep and the usefulness if amazing.

After months of searching online i found out that no one has ever put a York A/C compressor onto one of the older 2.5L Wrangler motors. I was surprised and excited about this because i knew i was going to be the guinea pig and a lot of trail and error was needed.

I will not bore you with all my trial and error details but here is what you need to get a York A/C Compressor onto a Pre-90 2.5L YJ motor:

Required Parts:

  • York A/C Compressor
  • A/C Bracket for York to Block for 4.2L 6Cyl
  • Alternator Relocation Bracket for 4.2L 6Cyl
  • Compressor Idler Bracket for 4.2L 6Cyl
  • Idler Adjuster Bracket for 4.2L 6Cyl
  • Idler Pulley for 4.2L 6Cyl
  • Custom Bracket For The Idler Adjuster Bracket (pics and measurements of mine coming soon) NOTE: This is only need for an OLDER (pre 90) 2.5L
  • Air Pressure Gauge From Grainger or Similar. I ordered THIS ONE because i like the flush look
  • Air Manifold from www.rockstomper.com (tell him i sent you please)
  • Misc Plumbing (personal preference)

To make a long story short, the passenger side of the 2.5L block is 100% identical to the older 4.2L motors and the 3 holes on the side of the 4.2L block that the compressor bracket attaches too are also in the exact same spot on the 2.5L. This means the 4.2L bracketry that i had for my CJ all converted over to the passenger side of the motor and the York and Alternator mounted effortlessly.

The only problem i ran into was mounting the idler pulley bracket to the drivers side of the block. As you can see in the pic below, the bracket needs to be moved over exactly 2" away from the block in order to clear the thermostat housing. I will have better pics and measurements of the custom bracket soon. I did all the measurements and such and sent them to Bud Rosenburger of BUD BUILT in Arcade NY to have the bracket made. I then had to move the front drivers side head bolt to the middle and use the middle head bolt in the front because it had a stud on the top and i need that to mount the bracket.

Still have tons of room with the York installed.

Here you can see the alternator relocated underneath the York. This is done via the 4.2L alternator relocator bracket.

Here is the idler pulley and the custom bracket from BUDBUILT to make it fit.

Here are some pics of the tank and the plumbing of the York

I decided to use the 2.5 Gallon tank from Brad Kilby because of the size, amount of fittings and ease of mounting It has a total of 5 3/8" NPT fittings for ease of installation at almost any angle It also, has cool brackets to mount it

Then Came the plumbing and wiring. Here are 2 schematics that i made for my specific setup using some pics from Glenn Bontlys Great Schematics. Check em out:

Here are some shots of the manifold and plumbing

How to ID your York to make sure its the Long Stroke 10 CFM one (model 210)

New belt setup

Alternator Relocation Bracketry and Water pump idler pulley adjustment bracket from a 4.2L

By using a Volvo York clutch you get a smaller diameter, therefore more RPM's which means more CFM.

Back To Onboard Systems