On board air, cheap, effective, fast.

[t0x1k]

Well, my A/C doesn't really work, and I don't want to shell out a couple hundred for an electric compressor. I read up on converting the A/C in the truck to air compressing. I never used the a/c anyway, plus I want to remove the condensor in the front to allow me to clean the mud from my radiator easier.

Our trucks are a little tough, they mount to the AC compressor using a block manifold, so there are no threaded fittings or barbs.Just 2 steel pipes. In order to connect it I had to cut the output hose and cut the pipe going into the accumulator for the input. The steel piping is exactly 5/8 OD and compressing fittings work great. The output hose doesn't have enough pipe but has enough rubber hose.

Parts list.
**1 Oiler
**1 Air filter
*I picked up a kit that holds a few oz of oil(and adjustable oil output) and a big air filter pluf regulator for $30 at harborfreight*
**1 3/8" HoseBarb by 1/4" MPT
** 5/8od compression by 3/8" MPT
**Pressure switch
** Blow off valve
**Check Valve
**Small air filter/breather filter.
3/8 Air hose 25'
gauges
wire 14 and 16 gauge
switch

You're going to need lots of extra fittings but that is entirely up to you. Just look at pic number 3 for example.

-First drain the ac system and piece out your set up before screwing everything together. Make sure nothing will touch the engine, exhaust, or fan.
-Cut the output hose, the one with the small canister and fitting on top, closest to the canister. Cut it right before the crimp.
-Next cut the steel tubing on the input hose leading to the accumulator right before the bend to go into the canister.
Remove the clutch power connection and remove the split loom tubing and cut enough wire to splice into, cut it off completely and tape or crimp a cap onto the ends of the wires from the main harness.
-Follow the wiring diagram for the clutch power.
-Next, screw the 3/8" x 5/8 compression fitting into the oiler on the output side of the oiler and attach it to the steel tubing of the inlet hose, tighten it good. Attach small air filter to the input side of oiler.
-Now the output hose, the hose is an odd size and a 1/2 hose barb is too big and 3/8 is too small, use a 3/8 hose barb and 2 hose clamps, it will seal trust me. Tighten it up good, from there the configuration is up to you, just make the filter the first thing after the hose barb fitting.

You can tap into the stereos 12v ign wire for the toggle switch over ride to prevent the clutch from engaging while the truck is not on. Or do like me and install a lighted switch.

I'm impressed, it pumped my 10 gallon tank to 100 psi in just around 30 seconds.

 

[adsm08]

Hmm. I may need to try this.

 

[Hahnsb2]

Did the same thing on the old 2.9 in my B2, it worked very well!

 

[Sasquatch_Ryda]

The compressor on the 2.9L will last forever set up like this...the Sanden style compressor on the 94 will eat itself up even with oil. I change mine out at least once a year....

 

[t0x1k]

Sanden was the pump used in most of the mods I researched and they had been running for over a year in some cases.
I've got it flowing with quite a bit of oil. I'm using ATF as I read its the best to use.

 

[Sasquatch_Ryda]

I've tried ATF, air tool oil, and engine oil...all have lead to compressors spitting out black/grey goo death and seizing.

 

[feellnfroggy]

I posted about htis a while ago, because I wanted to do it and got very few answers. This is an awesome writeup though. You should submit it to the tech library.

 

[slow96gt]

thats awesome i like that idea, ive never heard of this one, great write up to

 

[4.0B2]

The compressor on the 2.9L will last forever set up like this...the Sanden style compressor on the 94 will eat itself up even with oil. I change mine out at least once a year....

the sanden style? idk anything about this.. say i have a 92 4.0, is that one of the sanden style? will the OBA conversion work that compressor and last awhile?

 

[The_Dealer]

will it work for 2.8?

 

[Sasquatch_Ryda]

The 3.0 and 4.0L have the sanden compressors. The ones on the 2.9L seem to last forever. My buddy and me did the conversions at the same time 4 years ago (he has the 2.9L) and he is still using his original compressor still. I have been through 5 compressors in that time.

I have a York 210 piston style AC compressor I will be mounting under the hood to replace the sanden junk.

 

[martin]

I did the same thing on my 2.8 years ago. I used the compressor from some chrysler car and used air tool oil for lubrication, never had a problem.

 

[The_Dealer]

on my yj i used a york compressor and some kilby parts. man it was nice being able to run air tools on the trail if u have some breakage

 

[t0x1k]

Now that I've been tinkering with it, it's a good idea to put the check valve right before going into the tank, and use 2 gauges, one for the tank and one right after the air filter. The pump goes ape shit insane with pressure and flow that at 2k rpms the pressure builds up faster than it can fill the tank and blows the relief valve.
I'm going to see if I can make a switch that will be on while the throttle is at idle and off when the throttle is at a certain point, like the stock WOT switch.