York On-Board Air
By JJ Rodriguez
** This installation is used on an '89 YJ, while keeping existing A/C and using V-belts
Introduction:
I ventured into this mod purely by "boredom." I had already done other mods such as suspensions (SOA, buggysprings, etc), axles, gears, lockers, steering, etc; and frankly, I kind of got burned out on the ole same song and dance. I've read about people converting their A/C compressors to on-board air, and never really thought twice about it. One day, it kind of just clicked-- "OBA would be sweet!" I did a little research on some other alternatives such as the QuickAir models and the PowerTank solutions, but I quickly came to the consensus that those alternatives were just too expensive for my taste. Also, they would be too easy! I've always had this thing in being different and doing things the hard way (not a good thing :) Initially, I was naive on the subject of converting A/C to OBA and was a little intimidated. After doing some research on the thousands of write-ups on the web, I quickly figured everything out and decided I would get to work.
Initial Problems:
All the write-ups I had found on the web on York compressors were tailored for late model Jeep YJs & TJs. Also, not one of these pages was specific to my needs (you can usually find one). I wanted to keep my existing A/C and add the York. Each of these sites referred to Brad Kilby at www.onboardair.com. Well, I decided to check out his web page, and he sells some really nice products and kits!-- for LATE models!! The problem is that I have an '89 YJ 4cyl with A/C, running v-belts. All the pre-fabbed "kits" are for use with serpentine style belts and engines. Jeep seemed to change from "random" brackets from 1991 and on. Each of these engines used more or less the same brackets, pulleys and mounting points on the engine. Well, so much for buying a pre-made kit..... I guess I'll look for the York first!
In search of a York:
I had figured if I go ahead and find the York, then I would be "forced" to figure out a way to install it, since it would be staring at me every time I would go in the garage. There are literally _NO_ junk yards that are close-by to me here in Spring, Tx. They are all usually a good 45 minutes away and a hassle to deal with in general (atleast in Houston). I decided to pop open the yellow pages and search for 'used car parts.' Well, I found a semi-local (Tomball) used car parts store and gave 'em a call. They indeed had a York! Well I go down there, and the guy brings out an old Motorcraft (basically a rip-off of the York) unit with the biggest pulley I had ever seen, about 8 inches in diameter. This wouldn't do, so I had the guy go back and check one more time. Well, he found one York back there and brings it out. It had the two v-groove clutch attached (which I needed) and after scratching off some residue on the mounting plate, it was the 210 model! I turned the clutch over a few time to see if I got suction, and it seemed to work great-- I found a gem on the first try! I got the guy to give it to me for $40 plus a one year warranty. Of course, by the time I got it mounted, the warranty was near up, but that's beside the point. A brand new York goes for about $200 and a new clutch can cost from $80 and up. I know I got extremely lucky finding this York, as I have read stories about people not finding either the "correct" York, or cannot find a workable clutch. As soon as I got home, I tested the clutch with a car battery and it engaged, luckily. As I mentioned, this was the 210 model. There were three models made: 207, 209, and 210. The 7, 9, and 10 stand for the stroke length. The higher the better in the OBA sense. On to mounting...
Mounting the York:
Another problem that I had in addition to the aforementioned ones was that the way my A/C and alternator were bolted was abnormal. Maybe I had dealer installed A/C. The A/C was bolted to the head of the engine on the right side, and then the alternator was bolted to the side and above the A/C unit (Sanden compressor). So, not only would I have to find a mounting point for the York, but I would also have to find a new spot to mount the alternator. At first, I figured I would just fab up some new brackets and relocate everything. I took everything off and started doing some measurements. I came to the conclusion that there was just "no way" to do this right and safely. I figured there had to be some brackets that already pre-exist for a York application. So I starting looking at things from a different viewpoint. My 4cyl is actually an AMC 4cyl, which is modular to the AMC 6 cyl, aka the 258. I knew at one point CJ's came with York A/C from the factory at one point and that all AMC vehicles had an A/C option. I started snooping around on some AMC websites and I found these:
These were the factory brackets that AMC used to install York A/C on their vehicles (AMC Rambler, Spirit, etc). The left picture shows the York mount and the idler pulley, and the right picture shows how the alternator mounts below the York mount. Immediately I went in search for these brackets. As I said, there are not really any junk yards in Spring, so I went to the yellow pages. No luck. I decided before I go out venturing in far away junk yards, I would search the 'net. I found a dealer in old AMC vehicles and he had these exact brackets (the York mount, alternator mount, and the idler pulley and bracket). I bought them for about $80 with shipping. A bit pricey, however it saved me something more important-- TIME. A week later the brackets arrive and I dove right in. With a little hesitation and hope, I attempted to bolt the York bracket to the engine head-- and it fit perfectly! I proceeded to mount the York and the alternator, and everything looked good. However, remember how I wanted to keep my existing A/C? I basically traded in two problems for one. (better, but..... ugh!)
Mounting the Sanden Unit:
Now that I have the York and alternator bolted to the engine, all I have to mount now is the existing Sanden (A/C) compressor. The only logical place for me to mount it is to the side of the York compressor. Luckily, both sides of the York are identical and they each have four tapped holes to mount on to. All I really needed now was a flat plate to mount to the York, and weld on four "ears" to this plate to mount the Sanden on to it. Remember Brad Kilby's page www.onboardair.com? Well, I remembered that he makes an adapter plate to work with his existing York mounting plate, so you can mount a Sanden compressor instead of a York. After looking at some detailed pictures on his website, I deduced that this plate would be exactly what I needed. I went ahead and ordered the adapter plate ($40), along with a little faith that it would work. The plate arrived a week later and was plenty stout, as well as being zinc plated. And as I thought, everything bolted together very nicely! Here is pic of the final Sanden/York/Alternator "cluster":
More Problems (idler)...:
Just when everything started to come together, the idler pulley and bracket that I ordered previously didn't quite fit right on the 4cyl. The idler pulley bracket will fit, but its tight. When I go to install the pulley itself onto the bracket, it will not fit because the thermostat housing is in the way. Initially, I just replaced the housing with a 6cyl housing. The new housing fit fine, but with the new idler in, it would hit the power steering belt. The pulley really needed to be moved over about 3 inches away from the engine head. I did figure out that everything would work if I mounted the idler upside down-- now I did do this, but it was ridiculous. I opted for another alternative. I decided to mount a 3/16" x 2" x 12" piece of bar flat to one of the timing cover bolts and one of the alternator bolts. Before mounting the bar flat, I had to carefully measure where to drill the holes. The very bottom mount I ended up "slotting," so that it could rotate around the upper pivot bolt (the bolt right above the bottom)-- this was a pain in the ass. While doing this, you also have to make sure the flat doesn't hit the thermostat housing-- easier said that done. You can see the way it mounts on the bottom, next to the alternator in the above picture. The next thing I needed was an appropriate pulley that pushes. Since this IS an idler pulley, it also needed to be adjustable. The best pulley I found to work was a Jetta Idler CAM pulley. What makes this unique is that it has an eccentric middle, which it allows it to adjust off a single bolt. I bolted this pulley to the bar flat, making sure it would not come in contact with the thermostat housing. Below are some finished pics of the setup:
Plumbing:
All that was left to do now was the plumbing which is pretty straight forward. First, I needed an air filter for the suction port of the York. Some Yorks have different heads installed on them, and this one happened to have the "roto-spin"/jam nut kind, with preinstalled fittings. I simply needed something that would slip on. While at Advance Auto parts, I saw one of those ghetto-cool breather filters hanging on the wall. It's a knock off of a K&N filter. Anyways, it fit perfectly on to the pre-existing fittings, so I bought it. From the discharge port and on, it's pretty much up to you how you want to run things. Here is a list of parts I got:
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Pressure Switch (I got one of those "Square D" adjustable kind)
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Blow Off Valve - for safety
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Check Valve
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Oil/Water filter catch
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Air Gauge
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Quick Disconnects
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Misc. Manifold Parts
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Appropriate fittings
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Orange Rubber hose ($10 for 50' @ Home Depot)
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Lighted Rocker Switch SPST
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20 Amp Inline Fuse
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Wire
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Bunch of hose clamps
I ran my setup starting with the check valve, the oil filter catch, and then ran a hose to the manifold I built. Here are a few pics:
The reason for the Oil/Water filter catch is that some (most) Yorks expel oil from the internal oil sump. This simply prevents oil from getting all up in your air system. The manifold has my pressure gauge, along with the blow-off valve, pressure switch, front & rear outputs, and one future air-tank attachment. Like I said before, it's up to you and your needs. I like this setup, and it may be a little excessive. As you can see, I used two 'L' brackets to attach the manifold to my passenger fender. The wiring you should be able to figure out. My bumper has an integrated 2.5 gallon air-tank, so I ran one of my outputs there (along with a drain cock), and I also ran another output to the rear of my Jeep. I also found that those rubber nubs that go on chair feet work good as a debris cover for the disconnects.
Conclusion:
This is by far _THE_ best mod I ever did to my Jeep. I'll be honest, though, this was a BITCH to get it finally working, as far as the mounting goes. The York airs up FAST and runs power tools great! I'd really like to add another 5 or10 gallon tank somewhere on the Jeep, just so that the compressor doesn't have to cycle as often. Currently I have the pressure switch to kick on at 100psi and cut out at about 125psi. The average time to fill up the entire system from 0psi to 125psi (with the 2.5 gallon tank), is about 15-20 seconds @ idle. One of the best parts of this is that I didn't have to give up my A/C! I've been running this setup for a little over a year now, and I haven't encountered any major problems with my installation. Some people question whether or not I suffered a power loss, and the answer is no. The York free-spools while I drive, and doesn't take any power away from the engine. Even if it did, it would be so small, you would not even notice. If you have any questions, feel free to email me at grinch@alumni.utexas.net