Air compressor from AC unit

[fullthrottle]

Has anyone converted their AirCon compressor into an air pump?

I understand in some cases the freon gas lubricates these compressors, so you have to be careful to get one with an internal oil reservoir.
I've also been told that these things can crank out 400psi, so you have to be careful.

[BlakeJ]

there is 2 or 3 good threads on here relating to on board air, search "on board air" "endless air" or "sanden" and you will find them

Yes your correct unless you wanna muck around with oilers and oil catchers you need one with an internal resovoir. Sanden pumps are the most common, like the older SD508 which are hard to come around by now. i have the newer sanden which is the sd709 you just need to watch out with some sanden pumps that have a "V" in their name, they are variable displacement and will not work for on board air.

There is a bit involved in the conversion and after you buy all the gear usually works out about 3-400 bucks. I run a little air manifold off the tank that has a pressure relief valve (emergency valve) and other things like a guage and arb pressure switch (this turns the compressor on when pressure in tank drops below 80psi and shuts off at 100psi).

i havent quite finished building my system yet, still have to convert the compressor but here is a really good link that explains the conversion step by step http://www.jpmagazine.com/techarticles/ ... ir_system/

cheers
Blake

[fullthrottle]

here is a really good link that explains the conversion step by step http://www.jpmagazine.com/techarticles/ ... ir_system/

cheers
Blake

Interesting.
Do you know what pressure is held in the AC system normally?

[ice4x4]

here is a really good link that explains the conversion step by step http://www.jpmagazine.com/techarticles/ ... ir_system/

cheers
Blake

Interesting.
Do you know what pressure is held in the AC system normally?

Pressures vary throughout a refrigerant circuit but the HP cut out is normally about 20bar.

[skidmark]

here is a really good link that explains the conversion step by step http://www.jpmagazine.com/techarticles/ ... ir_system/

cheers
Blake

Interesting.
Do you know what pressure is held in the AC system normally?

system at rest,as in ac not on, about 50-70psi throughout system.when running theres two sides,high and low.low side approx 25-30psi and high side usally 120-150psi..although with no airflow through condenser(especailly on trucks with horton fan disengaged)high side can hit 350psi easily.

[fullthrottle]

Just been reading the workshop manual and thinking out loud here......feel free to comment.

Not sure why it costs so much to setup, if you get hold of a compressor with a seperate lubricant chamber then surely you can just use the existing AC button to engauge the magnetic clutch to turn the compressor on.

Sooooo, could you in theory have the setup as follows:

On the low pressure side, the compressor would just draw via air filter and non-return valve, the natural ambient air.
On the high pressure side would be a pressure relief valve, (maybe non-return valve), air tank with regulator for connecting air tools and pressure gauge so you can flick off the AC button when the tank reaches the desired pressure.

The manual states that the factory pressure relief valve is set to 520psi...Whow!! So it can surely get up there. Wonder what CFM you get out of these, could do some spray painting in the bush...hahaha

So the only thing I'm not sure about is if the low pressure side does actually require some pressure behind it, or the compressor will just draw the natural air in.

[skid]

Talk to Reece

[BlakeJ]

it costs a bit once you get into it, all the attachments etc. the compressor to start with is gunna cost you between 100-200 bucks, wreckers know what sandens are worth. Then there is your tank, i made mine myself. The money comes in all the fittings etc,
compressor - $120
Pressure relief valve - $22
arb pressure switch - $50
Air manifold - $37
x2 tool connectors - $24
non return valve - cant remember
there was also about 5 barb fittings, and air guage (and line and fittings to remote mount in the cab) the steel sockets for welding into the tank etc, if you want to do it right it adds up, if you want to do it real hori you can buy a stuffed air compressor and rob the bits off that but they end up looking like shit, ill add some photos on mine for ya if your want. But year i think including the compressor mine owes me about 350 bucks, that includes the mounting plate i had made by benT, (excellent job) to mount it and move my powersteering pump down as its a big compressor and on my little samurai.

I chose the 80-100psi switch as 100psi is what air tools are designed to run around as well as airhorns etc, im going to be running a rear locker off mine also

[BlakeJ]

o and yea my intake hose just goes straight into my airbox to avoid it sucking dirt or water.

The reason the variable displacment pumps dont work is because the require back pressure (like in the closed system of air con) to pump, well thats what the aircon dude told me

[De-Ranged]

Talk to Reece

Which one

If its me then.... I love how people over complicate things, your standard pump works and very well I'm talking inflating an empty 33" to 40psi in a mater of a few min
I have been told that the pumps are sposed to be lubed by the refrigerant and will crap out without lub.... I haven't had one die yet and if it did then its $20 at the wreakers for new one
I've always plumped them to a tank.... if you don't trust your welding a good source is truck wreakers and trailer air tanks, I normally run to the front bar, the intake I stick into the motors air filter
The only expensive bit is the pressure line between pump and tank take the output fitting and hose to hydrolic hose doctor and get him to crimp a length of 2 wire hose onto it.... if you talk universal currency they may have a length of second hand hose that will do the job get a fitting for the other end and male/female, weld the opposite fitting to your tank and a bsp fitting so you can put an air connector on the tank and your away
Don't worry about releif valves.... only turn it on when you need it and its hooked up to what your pumping.... oh and I've found out the magnetic clutch will slip (makes a nasty noise) if your stupid enough to leave it on without using the air


Cheers Reece

[Big]

What Reece said, cheap as chips to setup..Use any switch, relay, and a what I have is a 100 on and 150 off pressure switch and it'll stay on an off keeping the tank at a minimum 100 psi.
I also have a regulator down to 60-70 psi for the free spool and when you get that all sorted , you can then plumb in more gear as you need it ie lockers as it's all clean air from the air box. I also have an oiler inline ( suction side to pump) to keep it lubed and I havent filled it in over 3 years and still more then 1/2 full.. Mind you I have 2 spare pumps..
You must use rubber air line from the pump to tank as using the plastic line will get hot and soft and will just blow off not matter what you do to keep it on.. been there done that.. I ended up using truck air brake line.. good for like 400 psi Im told.. If ya wannt a pic I can try to take one for ya let me know Cheers

[fullthrottle]

Very interesting. I guess if the compressor isn't on for long periods of time like when the AC is required. Bursts just to top up the air tank isn't going to kill it.

PICs would be great, but I'll have a serious look at it. Was about to pull out the AC, but will keep the compressor there now.

Cheers

[kbjj]

I'm going to draw the air off the top of the motor (out of the catch can) to get 'oiled' air, and use bar work as my 'tank'. I'm guessing an oil seperator might be a good thing, rather than oiled air in tyres

[1justin]

ya may get some big spits of oil from the top of there cams flicking oil all the time also wouldn't that depressure the head and sump don't know if this is a bad thing or not, also if you don't run a relief valve at some point won't something go pop from to much pressure if these things are capable of 350psi, if you forget to turn off the aircon haha

[Maxfab]

Here is a link on how to modify york compressors
http://www.jedi.com/obiwan/jeep/york_oilmod.html

Will keep hunting for the sanden one

[sig]

i ran standard toyota pump for a few years , every so often i would give it an injection of slick 50 to keep it going ie at the start of a days playing .when i ralleyed and had a puncture we would just high lift jack the truck ,use the air for the rattle gun to get it off and then fix it on the rally site beside the hazard.This was back before bead locks were common and if there was no onsite puncture man available.you are welcome to come and have a look at the setup on my 40 if you want