On Board Air Revisited

[Hedgehog]

I left the York AC compressor on the 360 to use it in the future for an OBA system. I've been watching the Pawn and used equipment places for a small or broken compressor to use as parts. I finally found a small Craftsman compressor for $40. The tank is small, 2 gallons, the size I've been looking for. Due to the small size of the compressor it is rated at 110 psi. I originally wanted to run a max of AMC 150 psi and I believe the tank would handle the pressure just fine, but all the parts are rated for 110 psi. I'd like to use the pop off valve, shut off valve and the gauges. The question is, will 110lbs. on a small 2 gallon storage tank be enough air to be practical. My impression is the York compressor will product a bunch of air in a hurry. I'm not really looking for a shop quality system, some air on the trail would be nice. If 110 psi will be adequate all that is needed is a switch, some hose and an air/oil separator. Question is, would 110 psi and a 2 gallon tank be enough or should I drop by Grainger for a AMC 150 psi switch and pop off valve.

 

[hole]

Hedge, I'm a carpenter/framer and have raised the cut out psi on every compressor I've ever owned to AMC 150 , and only one did I have to change the popoff. You might get away with the current setup, and if not the popoff is an easy change out. I might be wrong about the tank, but I remember reading that all small tanks were designed/rated for 300 psi max. IIRC it was an OSHA thing, but again, I might be wrong

 

[Hedgehog]

Yeah, I think you are right about the tank. It is a solid little thing. Was thinking about this last night after posting. It is a relatively easy thing to change out a pop off and a shut off switch, so why not give it a try, if the system needs more oomph, switch'em out.

The next hurtle is. The tank is plumbed for 1/4" fittings (I believe) is that big enough? Seems small. That is the pump outlet to the tank is small (won't be used) and the pressure switch is small (the switch will go under the hood, not on the tank), but the gauge port and drain are bigger.

 

[Lumpy Grits]

1/4" is fine-
Make sure you also install a 'pop' off valve too.
BTW: These electric switches are built for AC current, and not DC.
That can play heck with the contacts within the switch. Buy the best switch-NOT the cheapest.
I have a hand throttle that I set at 1100 rpm for when I run'n the compressor or the winch.
LG

 

[hole]

Lumpy brings up a good point about the switch being for A/C, but every one I've ever owned was adjustable. Just lift off the cover and there should be an adjuster screw/nut for the cut out. I've even had some that had a separate adjustment for cut in and cut out

 

[Hedgehog]

This switch is or looks similar to the one sole by the guy that markets OBA on York compressors. It's a small preset item with 110 psi written on the switch. These same switches can be purchases at Granger. I know the ones you guys are talking about, a 2.5"x3" square box with cut outs for cable and a screw that's adjustable for pressure.

I was hoping that electricity would be electricity, especially since we are talking about 110v vs. 12v.

It's to late on the 1/4" ports. The tank had 4 ports, 2 - 1/4" ports and 2 - 3/8" (I think they are 3/8") common compressor sized ports. I threaded the 1/4" ports for a 3/8" fine thread, put a bolt in, cut them off and welded them up solid. I will be using the bottom port for air "IN" and a "T" for a drain. The top will be air "OUT". The tank will live under the CJ in front of the axle, there should be plenty of room there even considering the movement of the suspension. If not it will go under the passenger seat floor.

The tank will need to be flushed before final install. I'm not exactly sure how to do that properly.

The gauges and pressure regulator are neat little affairs, I think it will make a nice neat package under the hood. Now I need the elbows, filter and hoses to go from the compressor to the gauges.

 

[Lumpy Grits]

For hose, use the flex hose used for air-brakes.
Holds up better to the engine's heat
PLEASE-Be sure to install a 'pop-off' valve for safety.
LG

 

[Torxhead]

For a pressure switch, I use something similar to this:::Kilby Enterprises::, Plus check out that web site.
It will shut off at at 120 p.s.i., I had no filling problems even with a small air tank, 1/4" lines, and my oem style Sanden compressor, with 35" tires. I don't see any need for a pressure regulator though. The York compressors are great due to their size and their own oiling system. The hand throttle is nice to bump up the idle speed to get the compressor to work faster. I have my tank mounted under the bed above the rear axle.

 

[Lumpy Grits]

How long has your p'switch been in?
My concern is the DC power used will pit the contacts over time/use. I have seen them stick and pop the pop-off valve open.
LG

 

[Torxhead]

Lumpy, I have not had any issues with that type of pressure switch. I have had issues with using unloaders though, now I use a check valve. From what I have seen from Brad Kilby's stuff, it seems to be pretty first rate.

 

[Hedgehog]

Lumpy - From the very first post in this thread I included a pop off valve in my list of parts. I've also had a hand throttle for a year now.

Is the Air hose line for under the hood or the entire inside the body system with regular air hose being used for working as in a regular air compressor? Also, how many and where hose connections do you use. In a perfect world one up front and one in the back would be nice. Realistically one under the hood would work just fine and would be less maintenance.

Lumpy - not to worry, I have been working on the CJ. But not a solid day of it. the house needed cleaning something awful. I did set the rear brake lines back in their place and reassembled the guts in one of the drum brakes. A milestone of sorts was achieved. Gas was added to the fuel tank and the gauge seems to work, a big worry off my mind right there. I even started the beast. A little grinding or cranking to fill the fuel lines and filters, then the old gal fired right up, I'm pleased.

Torx - Kilby Enterprises is the company I was talking about in an earlier post. Maybe I'm looking in the wrong place, but the pop off valve they have is listed at 185 psi. The pressure switch is listed as "on" @ 120 PSI "off" @ AMC 150 psi. I might be able to get one like yours at Grainger.

 

[Lumpy Grits]

Good to know-THX.
My set-up has been go'n for almost 28 yrs now. I do like the adjustable pressure switch.
I also run a separator to put the oil back into the compressor.
LG

 

[Torxhead]

I guess I posted that without understanding it. When you set your system up consider that the compressor does get very hot and so does the air requiring a air line that can accept the hot air, where it is required. Plus the compressed air can get a lot of moisture in it which can collect in the tank. I am not really sure how much oil will be pumped out with that York pump. On my Sanden pump, I used a recirculating oil system and filter. I have seen a lot of onboard air setups and some are pretty scary. On the net a lot of guys have their air systems laid out for you to see and maybe help in your design, I am sure you have seen some of them.

 

[Hedgehog]

What do you guys use for an oil separator?

 

[Torxhead]

Here is a pic of my underhood and you might be able to make out some of my onboard air system.
I purchased a standard pneumatic system filter from a local outfit called McFadden-Dale, with 1/4" fittings. It did let a bit of oil thru though, and put up with it for awhile as it helped keep the inside of the air tank from rusting at least. I just had to drain it every now and then, but I did get tired of doing that. So I purchased a replacement filter that was for a oil coalescing filter from Grainger's and It seems to filter all the oil out O.K. The oil that gets filtered out is run back into the pump. I have here a pic of the one that Kilby sells just to post one up:::Kilby Enterprises::
I think setting up your own onboard air system takes some research, but is well worth it. I do know some guys that get by just fine with one of those electric jobs.

 

[Lumpy Grits]

Just a std deal with the drain plum'd to return the oil to the compressor's intake.
You will want an airfilter on the intake. I use a K&N crankcase breather filter with an old sock over it.
LG

 

[Hedgehog]

We all know that the York compressor spits a little oil that is caught in a filter of some sort. So here's my question. How do you put the oil back in? At first I figured there was a line plumbed back into the AC crank case (for a lack of a better word). Then I was thinking, "How does the oil get back in a standard AC application?" It must return with the Freon (or what ever) to the compressor which sounds like it would be acceptable to just dump the oil into the intake. Then how does the oil get back into the crank case? From the above comment it sounds like the oil is just put back into the intake making things even easier than expected.

 

[Lumpy Grits]

YUP-
I have a 'T' fitting plum'd in below the air intake and the oil gets push back in there.
What I do, is to just 'crack' open the drain on the separator and leave it that way so the oil recycles itsownself back into the comp.
LG

 

[Torxhead]

Mine sounds just like Lumpy's where the pressure line from the air pump goes to the onboard air oil filter, to a check valve, then to the air tank. The oil that is in the bottom of the oil filter goes into the intake side of the air pump controlled by a valve. I thought that the York pumps had their own oiling system. Getting back to pressure switches, I use a QuickAir2 #ps002 which comes on below 80 and shuts off at 105 p.s.i. which looks just like the one I previously posted.

 

[Hedgehog]

The York AC pumps are largely a dry system, but some oil gets by and should be returned or the sump needs to be refilled from time to time. It is the separate nature of the York pump that has me a little confused about returning the oil to the sump by just returning it to the intake.

Lumpy - is yours a York?