4x4Help.com - Your #1 Website for Off-Road help, tech articles, how-tos, pictures, and more!


  Getting Started
  Tech & How-To
  Parts Search
  Pictures
  Contact Us












Onboard Air Setup #1 (1994 Bronco)
 
 Well, as I have a disease, which involves spending lots of time and money on my Ď94 bronco, I decided I would go for some onboard air. There are lots of good write-ups out there, but none are too bronco specific. While most of the install criteria are the same, the mounting of the York in ours is a little different.

I started by pulling a York out of an 80ís Volvo. I actually had to pull 4 out before I found one that worked. You want to check two things before you purchase one from a junkyard. You need to check the magnetic clutch and that the thing pumps air. Take the wire that comes down the front of the York and put it to the positive terminal on your battery. Make sure the unit is ground on the vehicle somewhere. Yorks are self-grounding, so there is no need to have a grounding wire. When you hear the pop from the battery juice, the clutch mechanism should engage and turn with the pulley. The second thing you need to check is that it pumps air. To do this, either engage the clutch and spin the pulley or push in on the clutch and spin the pulley. When doing so, you should be able to feel a vacuum on your thumb when placed over the suction side hose, or hear air rush out of the discharge side. It also kind of makes a gurgling sound. Once these checks are done, you should be okay. Another thing you should note while doing these checks is that the pulley spins freely. I opted for the 10 series York, but they also have smaller stroked models that will work, just not as well.

OK, so now you have a working York. Now you need to figure out how to mount the thing. The easiest place to mount them is on the alternator side of the motor. There is one brand of mounting system available through Sabreforce for the two bolt mounted alternator on the pre 92s. Jim makes a very nice quality mount, but does not make one for the 3 bolt mounting system on the later model alternators.
  •  2.5 gallon air tank - purchased at Kilby Enterprises. 60 bucks
  • Air Lines - I got mine CHEAP at Costco 100 ft for like 12 bucks, used 50 ft
  • Coalescing filter- purchased at Grainger 30 bucks
  • 3 way manifold, pop-off valve, Pressure Gauge, lots of fittings - purchased at Orchard Supply Hardware and HomeDepot. Not sure, but around 60 bucks
  • Pressure switch - purchased at Kilby Enterprises or Grainger 40 or 50 bucks I think
  • Check valve - purchased at Kilby Enterprises or Grainger 12 bucks
  • Double Pulley for alternator - purchased from Kilby Enterprises for 40 bucks
  • New V style belt for 13 bucks at Autozone

    This is basically what you need to make a system. I started with the tank, and there are several ways to do this so you need to pick the one that is best for your budget and style. In an effort to keep things simple, I bought a new tank from Kilby Enterprises. There are cheaper ways to do it using tanks out of semis, etc. or fire extinguishers or whatever. You can do this, I just elected to save the time and effort and spend 30 extra bucks as my patience were wearing thin by the time I got to the tank (I actually did the tank last, but knew what I was going to use). I mounted the tank behind the t-case and almost directly underneath the back seat. The tank came with mounting holes, so I just had to drill four holes in the flooring and buy the appropriate bolts. The hardest part of this install was cutting the heat shield for the exhaust system out of the way. Of course I could not find my cut off wheel for my grinder and did not feel like making a trip the local ACE, so I ended up using a combination of tin snips and my Dremmel.

    Next I mounted the York and started running my lines. I highly suggest taking the time and detailing your system out on paper prior to the install. I had a hand drawn schematic of how I wanted everything run and where all the fittings, filters, etc. would be. I then layed it all out on the floor before I installed it. This saved on the install time by quite a bit. Coming from the York, I put all my hardware inline. First was my coalescing filter I bought from Grainger, which connected to my check valve via a 1-inch connector. From there I ran a 1.5-inch connector to a three way manifold.

From the manifold I ran 1.5 inch pressure gauge, a 1/8 inch line to a remote air gauge inside the cab and a 1/4 npt air line down and along the drivers side frame rail to the tank.

On one end of the tank is the supply line, and on the other ends four ports I have two lines coming out to either bumper, the pop off valve (pressure relief) and the pressure switch.
( sorry for the bad picture )

The pressure switch has the on/off switch coming from a relayed switch in the cab and a wire that runs back to the York to turn it on and off. One air line runs back up the driverís side frame, into the frame near the motor and the female coupling sits inside the frame. I have a small piece of rubber sheeting inside the frame rail to prevent water and dirt from collecting there and protecting the female.
The back line comes from the tank, over the gas tank and through the plastic valence between the rear bumper and the bottom of the tailgate. I cut an X through the plastic to slip the hose through. What is nice about this is that I can push/pull the line out of the plastic to keep it protected and out of the way while wheeling, etc.

You will quickly gain friends you never knew you had. I did have a few technical difficulties early on however. The first difficulty I had was making sure all the fittings would work. The check valve I got was 3/8 while most everything else was 1/4 NPT. This is where detailing and laying out prior to install saves a lot of time and successive trips back to the Home Depot. The second problem I had was my own fault. I thought it would be cool to remove the double layer rubber pipe off the discharge side of the york and clamp on the very thin air line with radiator clamps onto the stock York fittings. Do you see the problem yet? I had to cut off the crimp on fitting to remove the old line. See it yet? Well, after the York would run for a bit and start getting hot, the air line I put on would blow right off the fitting. So I tried two radiator clamps. Still did not work. The line would get too hot and slide right off. So I am going to have a new line crimped on like it was.

Overall, I am extremely pleased with this system. It is a never ending supply of air, works fast and does not need to cool down like the electric units do. It is a fun project and costs around 200 to three hundred bucks depending on where and what you buy (new versus used) which is comparable to CO2 and Electric units.

Back To Onboard Systems