Tofer's OBA write up
 

OK so several of you have asked how i have my OBA set up.....
i'm using the stock 3.4 AC pump but this should work with any AC pump.

lets start with the flow of air. First starts with an autozone clamp on 1/2" air filter. that that goes into a Norgen Port 07 Series Micro Fog Lubricator Transparent part number L07-200-MPAA which is filled with ATF.
http://i629.photobucket.com/albums/u...c/0e052369.jpg
http://i629.photobucket.com/albums/u...c/8cf50184.jpg
that then goes through some 1/2" air hose to the Low Pressure inlet of the Air Conditioner pump.

the high side compressor comes up into 4 way T. (shiny blue thing hardly seen in the lower right of pic, i'll try to get a better pic tomorrow when its light)
http://i629.photobucket.com/albums/u...c/de90c4c4.jpg
the Viair pressure shut off switch got threaded into 1 ( I bought a too high of a switch. i got a 110psi on / 145psi off... but the system only gets up to about 120psi at idle... i need to switch it out to a 90/110)
the Pressure gague got threaded into another port on the T,
and the rest of the 1/2" hose goes into the last

that then follows the frame down to back of the truck
http://i629.photobucket.com/albums/u...c/507e72ae.jpg

you want to keep the oiler and the water/oil separator as far away as possible to make it work the most efficient. so the separator is located in the rear of the truck
http://i629.photobucket.com/albums/u...c/74c28151.jpg
(i just noticed i'm missing an hose clamp.. opps :hillbill:)
I have a Norgren Ported General Purpose Manual drain Trans. bowl part number F07-200-M1TA
http://i629.photobucket.com/albums/u...c/5577eb4d.jpg

that then connects to the end connector.
http://i629.photobucket.com/albums/u...c/c8c3de9c.jpg

i have quite a bit of slack so that i can pull the connector out if i need but ususally it just stays tucked up on top of the gas tank.


i got all the parts at a local air compressor shop.. i told the old guy who's been selling this stuff for years what i wanted to do and he said follow me, and took me through row after row after row of parts in old cardboard boxes until i had everything i needed. all together it was about 80 bucks.


as far as wiring:

i have a single wire running down to the single wire on the AC pump from the viair pressure switch. that then *will* go to a relay and then to a switch in the cab but for now, since the pressure switch doesnt work (it never builds enough pressure to turn off) the wire just goes up to the battery area and i just jam it in to the positive terminal when i need air. my air chuck is set to always flow so i dont overload the system and i dont run it when i dont have the chuck hooked in.

Nice, good job man!

Just so I understand the pressure switch is what controls (or should be controlling) the AC clutch to turn on/of the compressor right? I'm guessing it's somewhere around a 120 psi switch and the AC cannot get to 120 on only something like 110psi?

^You've got the right idea. But wrong numbers. He said his pressure switch comes on under 110psi and turns off when it reaches 145, which never happens in this config.



to the OP. Have you run this setup very much? I always thought that a standard A/C pump required more oil than that. This write-up makes me glad I hung onto the compressor from my 4.3.

thx numbchux, somehow I missed the numbers.

i've been running this setup for 2 years now.. and have had no issues. i have the flow rate on the oiler turned up probably 5/8th of the way to max which puts about 1 drop of oil into the air a second. knock on wood, but i havent had any problems but i do listen for any strange noises. the most i've done at one shot was 4 35s and 4 37s all coming from around 12-15psi back up to 32-35 and had no issues.

it works great when going to the lake/river/snow and i want to bring intertubes... i just bring them deflated, fill them up there, and then use my quick deflates to flatten them again before going home

Verry nice!

were you ever able to get a better picture of your 4 way T?

If he doesn't, I do :D