O.B.A. ?'s

[FatMan]

okay i was wanting to do this to my rig here pretty soon. im just going to set it up without tank for now and will add the tank later. out of all the research i've been doing "Nobody" your the clearest thank you. i have a couple of questions still cuz im alittle slow.

1. just so im straight- with a stock a/c compressor 1st i need fittings that will go from the compressor to a "T". from the "T" i need (2) female quick diconnects were i can route hoses how i choose.

my plan from there is to route (2) seperate hoses (1) to the front and (1) to rear both with female quick disconnects. i will have a length of hose that i carry with (1) side male connector and other with air fitting so i can go from front of rig to back of rig to fill tires/ect.

2. i want to filter my a/c compressor so will any intake filter work? i know kilby makes filters for YORK'S but can i use what there using for a stock unit?

3. will the engine oil hurt the compressor? i know they make compressor oil. how much to add and where to add?

4. if i decide to add a Coalescing Filter for filtering the air will that catch all the oil i put in to lube the a/c compresssor? will it mess up the Coalescing Filter or is that its job?

5. at this point with out tank will i need a pressure switch. im thinking i wont cuz theres no tank to regulate pressure.

6. if im not using the idle to move more air do i need the DPDT relay?

7. a/c low pressure cut out switch i know i have to bypass it but can i just cut it out and leave it open or does pwr still have to be routed through the wires?

8. what is a free flowing chuck?

sorry about all the questions at once but i really want to understand this right the first time and get it going.

[Nobody]

okay i was wanting to do this to my rig here pretty soon. im just going to set it up without tank for now and will add the tank later. out of all the research i've been doing "Nobody" your the clearest thank you. i have a couple of questions still cuz im alittle slow.

If you are not going to use a tank, then the easiest thing is to use a single hose and free flowing chuck

1. just so im straight- with a stock a/c compressor 1st i need fittings that will go from the compressor to a "T". from the "T" i need (2) female quick diconnects were i can route hoses how i choose.

my plan from there is to route (2) seperate hoses (1) to the front and (1) to rear both with female quick disconnects. i will have a length of hose that i carry with (1) side male connector and other with air fitting so i can go from front of rig to back of rig to fill tires/ect.

If you use female connectors, your system will build pressure, so you would have to use a cutout switch. While this will work, you'll find that the pump cycles on/off very rapidly while airing up. I can't imagine the switch will hold up to that for long.

2. i want to filter my a/c compressor so will any intake filter work? i know kilby makes filters for YORK'S but can i use what there using for a stock unit?

I imagine any intake filter will work as long has you have a way to connect it to your pump. If you are asking if you ports are the same, I don't know, but I doubt it. You should be able to get brass fittings to make it work at the hardware store.

3. will the engine oil hurt the compressor? i know they make compressor oil. how much to add and where to add?

What compressor are you using? I don't think engine oil will hurt anything. That's what I used at first...then I pretty much quit oiling. When I switched to a different compressor, I tore down the one I had used for like 8 years. I didn't find any signs of damage. Take it for what it's worth. The way I look at it, if it blows up, I'll grab another for $15 at the junk yard

4. if i decide to add a Coalescing Filter for filtering the air will that catch all the oil i put in to lube the a/c compresssor? will it mess up the Coalescing Filter or is that its job?

There are filters specifically for filtering out oil.

5. at this point with out tank will i need a pressure switch. im thinking i wont cuz theres no tank to regulate pressure.

If you don't have a free flowing system, yes you need a pressure switch. That's what turns your pump off. Otherwise it will build pressure in the lines until something blows. A popoff valve is a good idea to.

6. if im not using the idle to move more air do i need the DPDT relay?

That DPDT relay was just something I came up with to swith the polarity on my idle control solenoid for kicking the idle up when the pump comes on. So no, you don't needed it. Also there are one wire solenoids you can use instead. I was just using what I had. This mod also required that I cut the harness which would affect emissions, so really I wouldn't recommend it for anyone. Just what I did.

7. a/c low pressure cut out switch i know i have to bypass it but can i just cut it out and leave it open or does pwr still have to be routed through the wires?

cut the wires and connect them together. You only need to do this if you are using the switch on your dash.

8. what is a free flowing chuck?

Air chucks are the part that connect to the hose to so you an stick the hose on the valve stem. Free flowing chucks blow air constantly, and won't build pressure in the system. That's how you can avoid needing a cutout switch.

sorry about all the questions at once but i really want to understand this right the first time and get it going.

That's why the forum is here

[FatMan]

i will be using the stock b2 a/c compressor just like your write up.

1. at the "T" in your picture on the main page are'n thtose female connectors (quick disconnect types)?

2. okay i understand what a air chuck is, but what is a free flow chuck? okay so i understand this- if i run a free flow chuck when the a/c compressor comes on it will blow air out until i hook a hose up?

[Nobody]

i will be using the stock b2 a/c compressor just like your write up.

1. at the "T" in your picture on the main page are'n thtose female connectors (quick disconnect types)?

Yes they are....but I was also running a tank, and those disconnects were there mostly for ease of removal. One line went directly to the tank, the other the grill up front.

2. okay i understand what a air chuck is, but what is a free flow chuck? okay so i understand this- if i run a free flow chuck when the a/c compressor comes on it will blow air out until i hook a hose up?

I'm not sure you do understand what a chuck is.... It's the part that attaches to the hose. You need one that will allow air to flow freely whether it is connected to the tire or not. If you aren't using a cutout switch, you CAN'T let the system build pressure. I think the correct term is OPEN or FLOW THRU CHUCK

[FatMan]

ohhh!!!! i did'nt know they made those to flow air all the time. i thought they were always closed unless fitted to something. cool!!

i dont need the pressure switch unless i run a tank right or can i run it on a line and use it without a tank like i want to?

[Nobody]

Yep they make them...but they aren't as common in the stores.

The absolute simplest system you can have would be

Compressor > Hose > FLOW THRU CHUCK >Bypass low pressure cut out > Hit dash switch > PUMP AIR = CHEAP!

If you choose to complicate it more than that, that's up to you. Wire in a cutout switch and use a standard chuck. Add a tank, filters guages, air manifolds, arb's etc.....As much money as you want to throw at it.

[FatMan]

Compressor > Hose > FLOW THRU CHUCK >Bypass low pressure cut out > Hit dash switch > PUMP AIR = CHEAP!

cool i got it..

just one more question where do i find the low pressure cut out switch? is it the wires that go to the compressor itself?

[Nobody]

It's on the passenger side by the heater box. There should be a small round bottle the size of a liter bottle. You should see 2 wires going to it. Splice them together and rock and roll.

[FatMan]

your still the man thank's!!!!

[Nobody]

So get 'er done and let us know how it works...... should take you all of 5 minutes to splice those wires and pump some air.

[Nobody]

Are you Carbed?

[FatMan]

injected...

[FatMan]

okay everything is ripped out and the a/c unit is filtered. i used one of the existing hose from the a/c unit used to pump air. i fitted it with a male air hose connector.

as for bypassing the low pressure cut out i just used that switch. it seems to be a normally open switch by removing the screw and spring from the middle of the switch i makes it normally closed. i just removed switch from bottle, screw/spring from switch, and connected the switch back. i did'nt get a chance to try it out yet cuz it's late so i'll have at it in the morning and give you guy's a report.

thank's

[FatMan]

by the way how much oil should i use to lube pump and does it go down the filtered side?

[Nobody]

I initially fed a cap full of oil into the pump while it was running. Then as time went by, I became more confident, and oiled it less and less, and finally ignored it all together. If I may toot my own horn.....I was one of the first folks around running OBA, so I really wasn't sure how long a pump would last. I first got the idea from a magazine in 93/94.

Keep in mind these pumps do go bad......even when used as A/C, although A/C operates at much higher pressures. Assume your pump will die at some point. But who cares when you can get another for $15 at the junk yard.

Also they get hot when pumping. I mostly aired up my own tires and that was it, ocassionally aired up a few other folks. I tried to give the pump a little cool down time if I was doing more than one rig. Necessary? I dunno....

Is oil even necessary when used as OBA? I don't know, but at this point I don't really think it is. I'm not building houses, just airing up a couple tires.

Here are some pics of my old BII pump after I tore it down. While the pics don't show it, you can still see hash marks on the cylinder walls.

Pretty cool pumps, they are 6 cylinder!