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York OBA TJ Installation


All of the above instructions were accomplished at my leisure over the course of a months worth of weekends.  This was done to insure that I had at least two days to complete a particular portion of the project and to insure that if anything went wrong I would have sufficient time to fix the problem in time for Monday morning work since my jeep was my daily driver.  Once all the above preparations were complete, a two day weekend was set aside to do the next final steps.

Requirements for these final steps include the Brad Kilby bracket kit, York compressor, Air Manifold module and Oil Removal Filter/Check Valve that were all ready prepared from the previous instructions.  Also required are the 3/8" Insta-Grip hose, v-belt, Kilby alternator pulley, 4 - female Quick Connect couplers, 2 - 1/4" NPT female hose connectors, 6 - 1/4" NPT male hose barbs, Teflon pipe thread tape, male/female wire bullet connector, rubber mallet, wire stripper/cutter/crimper, all weather tape, masking tape, anti-seize,  assorted combination wrenches, sockets extensions and ratchets. 

Note: This would also be a good time to replace the number 1 sparkplug.

The instructions included in the Brad Kilby kit are very good.  Follow them.

1.  Disconnect the battery.
2.   I applied 1" of masking tape to the idler pulley belt tension bolt threads to mark the future reference spot I would re-tighten the idler pulley tension bolt to for proper stock belt tension.
3.   Loosen the serpentine belt by loosening the idler pulley bolt.  See Figure 1.


Figure 1

4.   Turn the tension bolt counterclockwise until the belt is really loose.  See Figure 2.


Figure 2

5.   Disconnect and remove the alternator.
6.   With a 7/8" or 22 mm socket and air impact, remove the stock pulley and install the pulley included in the Kilby kit.  See Figure 3.



Figure 3

I've heard that trying to remove the pulley without an air impact can be extremely difficult and could cause damage.  This is not to say that it can't be done. If you don't have an air impact, then take the alternator and new pulley to the nearest mechanic or automotive store to have the new pulley installed.  Also, if you are going to replace the number one sparkplug this would the time to do it since the sparkplug is difficult enough to get at under normal circumstances and would be even more difficult to get at after the OBA install is complete.

7.  Re-install the alternator and wire connections, torque the bolts to 41 ft. lbs and reposition the serpentine belt.  Do not tighten the belt yet.
8.   Remove the four factory bolts holding the AC compressor and carefully lift the compressor and insert the provided Kilby spacer between the compressor and compressor mount bracket on the two inside bolts and re-insert these two bolts loosely (a couple of turns is all) to help hold the spacer in place.  See Figure 4.


Figure 4

9.   Lift the end of the compressor closest to the fender and insert the main bracket between the AC compressor and compressor mount bracket and snugly re-install the two factory bolts.
10. Now remove the first two inner factory bolts and, with anti-seize on the threads, install the two longer bolts with flat washers supplied in the Kilby kit.
11. With the 2 Kilby kit 5/16" x 1" bolts, 2 - nyloc nuts and 4 - flat washers secure the support bracket to the main bracket, make the necessary final adjustments and tighten all six bolts.  The four compressor bolts should be tightened to 21 ft. lbs.  See Figure 5.



Figure 5

CAUTION.  Do not over tighten the four compressor bolts as they are easily striped.

12. Check the AC line on top of the compressor that sits next to the main bracket.  Mine required a minor adjustment (1/4" or so) to insure the AC line was clear of the main bracket.
13. Install the York compressor to the main bracket utilizing the four provided 3/8" x 1" bolts and washers with anti-seize applied to the threads.
14. Re-tighten the serpentine belt to the previously marked position and tighten the idler pulley bolt.

I felt it necessary to check for fender and hood clearance and was glad I did.  By purchasing belts made by different manufacturers and keeping all receipts, I had a selection of different length belts.  It may also be necessary to purchase v-belts that are 1/4" to 1/2" longer or shorter for a wider selection.  The idea was to raise the compressor as high as possible to tighten the belt and still have at least 1/2" of hood clearance.  I was determined to not have to cut my fender for clearance between the compressor and the fender.

I used clay between the hood and compressor fittings to determine hood clearance as well as a drop light in the engine bay to see what I was doing as I slowly closed the hood with each new belt tried.  This was a long drawn out process of changing out belts till I found one that gave the best clearance between the hood, York compressor and fender.  This process insured I would not need to cut the fender.  However, when all was done, there was still some question about the clearance between the York compressor and the fender.

A trustworthy person was required to do one last check of the fender to compressor clearance.  I had this person (my wife) set the parking brake and start the engine and put the vehicle in gear.  While I watched the clearance between the compressor and fender, rpms were taken up to approximately 1700.  The engine would torque to the passenger side at the higher rpms.  What I found was that the York just barely touched the fender, in the position indicated (See Figure 6), leaving the smallest little scratch right where I needed to make the required adjustments.


Figure 6

The compressor was removed and with a rubber mallet (so the fender wouldn't be scratched) I pounded the area that the compressor contacted until I had 1/2" clearance with the engine torqued.  This took several attempts of installing and removing the compressor and v-belt until I was satisfied with the results.  See Figure 7.



Figure 7

York compressor installed, all bolts and belts rechecked and one last check of the clearances, it was now time to start getting excited.  Wow, How cool is this?  See Figure 8.



Figure 8

15.  Install the previously fabricated oil removal filter/check valve bracket to the compressor and mount the oil removal filter/check valve module into place.  Also connect the oil removal filter return line to the oil fill plug adapter.

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