A/C Compressor as Onboard Air

[Chris]

My A/C doesn't work though I believe my compressor still does. I've read about converting it to an onboard air system which sounds pretty cool, anyone have first-hand experience with this?

[Funrover]

What compressor do the Toys have? I have done it with an A-6 out of the old Chrysler cars. They have a oil valley and that makes it easy!! What questions do you have?

[Brody]

If you use the Toyota compressor, you will have to put an in line oil drip adjustable oil drip feed in the intake side or it will starve for oil and lock up. Set this up for a fast drip. You will also need to run a dissicate (sp??) filter on the other side to keep water out of the line. These are all standard 'DAYTON' parts and you should be able to find them at NAPA or WW Grainger. Northern Tool also carries them. Buy some AC oil at NAPA as you will need it to top off your in line oiler every now and then.

Plumbing is simple: you have an intake and an output. Buy a cheapy valve cover intake filter for the inlet side and put it right after the water filter (filter at the end of the hose). Mount it up high. Run your outlet side to an air tank with a pressure relief valve or just an air fitting.

Electrical: You can run an in line pressure switch that regulates the pressure to your tank if you want to. Just split the signal from the switch on the AC and run it through the pressure switch. I just ran a switch from my clutch on the AC compressor and stuck it under the hood. I can only turn it on with the hood open, reminding me that I have the switch turned on. Too easy to burn it up other wise.

If you want to adapt a YORK (cheap at yards-about $30) to work, this is the ticket as you get more pressure out of them and also they have an internal oil reservoir that you can fill up. Other than that, the York plumbing and electrical are the same. There are many write ups on pirate 4x4 that explain this.

I am running the Toyota set up on mine as a back up air supply. It has worked pretty well, but the oiling is VERY CRITICAL! I also do not have a tank or an in line pressure wsitch at the moment, though either would be easy to add. A multi port manifold is available through Northern Tools, too, that is pretty handy to have.

[Brody]

I just posted up a whole bunch odf additional resources for OBA. Check them out as there is a lot of info on doing the AC conversions. Most of the info is for York or Saginaw pumps, but pertains to any AC pump conversions. There are some really good write ups. Keep in mind about the Dayton oiler for the Toyota pump as it is very critical!

[Chris]

Thanks Pete, lots of good stuff there. I'll be checking out my compressor to make sure it's good and then pursue this. I like using the Toyota vs York simply for the ease of mounting.

[Brody]

You are welcome. I have been using mine for about 3-4 years. Burned one up because I didd't set the drip rate on the oiler to 'flood' which is why I mention the oiler a lot. I supposedly have a copy or the part numbers that I used for mine and I will post them if I can find them. Otherwise, just go to the online Northern Tools and look under compressor/ parts/fittings and you will see them. They are probably listed very near the condensors and look almost identical. They will have an adjustable allen or other head in the top for setting the drip rate.

When you adjust this, set it so that it flows about 2-3 drops a second...about as fast as you can say 'drip, drip, drip' and you will be set up pretty well. This will only drip when the clutch is engaged and the pump is actually pumping. Make sure that you get a clear one (I don't know if they sell any other style) as this is the only way to check your oil level. I bought a small bottle of AC compressor oil (NAPA) 3-4 years ago about the size of a standard can of 3'nOne and still have 3/4 of a bottle left. You won't use much.

As far as the electrical on the Yota pump, you only have one wire to split as the pump is grounded to the motor. I used a very simple switch (and a seperate ground, which I also used) with an in line fuse vs a relay because it was easier and also because I have all my auxiallary power run through a breaker. I also knew that I wasn't going to have it be an auto on/off and that I was going to be manually switching the power on and off. If you plan to run it with a pressure switch and a tank, by all means run the power through a relay. If you plan on using you in dash switch. Run some sort of light where you can see it other than sitting in the driver's seat. These are extremely easy to leave on and not that easy to hear with older damaged ears....

[Chris]

Good stuff Pete, if you run across the copy of the part numbers that I used that would be nice. I have a couple things ahead of this - ARB in front, LSD in back, sliding rear window refurbish & install (my future A/C) - then OBA.

:cheers:

[Patrolman]

I performed the same mod on my previous Scout II. I didn't oil it at all. Always worked great. The 87 Toyota truck has the same mod from the previous owner. Seems to be seized as I goofed around with it in the fall. Again, no oil setup. I will have to remedy that. It would only be as an emergency backup anyways. The actual plumbing and wiring is easy.

[Brody]

Chris

Here is the link for the inline dessicant dryer:

http://www.drillspot.com/products/43380/Speedaire_4ZL08_General_Purpose_Miniature_Air_Line _Filter

You can get the same thing at Home Depot or Lowe's for about $11-13. The oiler looks exactly like this except that it has an allen or other adjustment screw at the top part.

Here is the link to the inline oiler site:

http://www.directindustry.com/industrial-manufacturer/air-oiler-76916.html

You should be able to find the same parts at WW Grainger or even NAPA. General Air Service and Supply might carry these, to as they are fairly universal.

[Chris]

Hey Pete-

I have the Speedaire 4ZL57 Miniature Micromist Lubricator and Speedaire 4ZL08 General Purpose Miniature Air Line Filter ordered from the info you gave me a while ago. I could have gone cheaper but these weren't too bad.

My understanding is the Toyota compressor will put out between 90 - 120 psi which sounds more than sufficient for me. It doesn't seem as though I'd need a tank but wonder how small I could go and still use one efficiently.

[Brody]

You should be able to use anything from one gallon on up, with the 2 gallon size being about the best as far as practicality, mounting size, etc. All you are trying to do is get it to where the compressor doesn't run full time when you are filling tires or using it. The compressor will fill the tank and only cycle to keep the tank full. You will fill tires, etc much faster with the addition of a tank of any size and also have the ability to reseat tires.

Unless you have a tank already, I would look into the shops that repair air compressors and air tools. I would bet that they have a little stack somewhere of air tanks that the compressor was just too costly to replace on lying around...Yes, the compressor will put out around 90psi at idle, but if you want it to put out more, a hand throttle might be the ticket. Once you get above idle, the AC will put out around 120psi.

Remember to set the oiler up so that it drips at a pretty good clip, too! Toyota AC love their oil!

PM me if you run into trouble or have questions..

[Chris]

I'll do that Pete, thanks. I'm just gathering parts right now. I'll keep my eyes open for a small tank. It looks like Northern Tools has a variety of manifolds and gauges.

[Brody]

The Northern Tools manifold is a really nice item to have. It'll allow you to plumb just about everything and you can run your cut off switch in the manifold, too. All the rest of the fittings are cheap at Depot or Lowes.

[Chris]

Cut off switch? I need a pressure relief valve don't I?

[Brody]

YEs, you do need a pressure relief valve. The shut off switch is plumbed in as the compressor (whatever you use) on/off should you want it. It basically tells your compressor to turn on when the pressure gets low in the tank, thus keeping the tank pressure up to a certain number of pounds. I don't like them, myself as it is just one more thing to go wrong, and instead wire a manual switch.

One of the things that you might do when you use a tank is to put a two way fitting (T) on it and set it up so that you can fill the tank with a regular air hose from either a home standard compressor or via an air pump. This way, instead od cycling your AC compressor to fill the tank, you can fill the tank at home before a run and just use the AC compressor to keep the pressure up in the tank. Save wear and tear on the AC compressor as you are starting off with a full tank to begin with.

Just some thoughts...

[Chris]

Some conversions mention using a check valve, what do you think? I've decided to use a 1 gallon tank (yes, it's small) since I have a spot for it under the hood.

[Brody]

I think that you will be fine just using the pressure relief valve, but the check valve will keep air in the tank and prevent it from bleeding out. A pretty good idea, but I have no idea of the cost..couldn't be too expensive or that hard to plumb in.

I was messing around with mine today as I needed to reroute some lines because I need to remount my tank. I took it out when I bobbed the bed and had to find a spot I could squeeze it in. Just out of curiousity, I replumbed it minus the pressure relief valve (I have mine on the same style manifold that you got) just to see what would happen. I turned the AC on and within a minute blew a hose. FYI, at idle the AC puts out around 80-85psi and the hose blew out at 130psi, still at idle. There wasn't a tank to fill, just some lines to the front and rear. I reinstalled the pressure relief valve and fixed the hose. The relief valve cut loose at around 140psi, just like it is supposed to do.

If you want to run some fittings, use the standard (air chuck) fittings and some 9/16 washers as spacers. If they are going to be exposed, use rubber bike handle covers that you can get at WalMart for $3-4 and cut them down to size. A little lithium or dielectric grease on the inside makes them easy to get on and off. Shoot the fitting with some WD before slipping the covers over them.

[Chris]

I also do not have a tank or an in line pressure wsitch at the moment, though either would be easy to add. A multi port manifold is available through Northern Tools, too, that is pretty handy to have.

Hey Pete, getting back to this since I've been gathering parts. Along with the parts you gave me numbers for I've been using this explanation because it makes sense to me: http://www.4x4help.com/tech/oba1.htm

Does the air tank act pretty much like a pressure stabilizer with the pressure in it varying while the output stays the same? I'm not sure whether I want one or not. My intended use is pretty much just for airing up.

[Brody]

If you have a tank, airing up your tires will go faster and, overall, there will be less wear and tear on your AC compressor. I have used mine (and others that I have done based on the York) minus a tank with no problems. The choice is pretty much yours.

You can always carry a small tank on longer trips if you want to and just plug the AC into it.

After having my tanks on and off for the last number of years..mostly off...I just recently remounted my air tanks. Will I see much of a difference...probably not a great deal, but airing up my big meats will go a little faster.