twstdtj
01-16-2007, 11:49 AM
Well, I got bored last weekend and decided to convert my stock AC compressor to an OBA setup. Heres roughly what you'll need (may vary depending on how you decide to set it up) you should be able to do this under $70 including tank and everything. I did it for under $20 as i had most of this stuff already laying around in my garage, and my tank was already installed. Disadvantages to me none. To you, you will loose your AC, but if your like me and dont run with a top or doors anymore, then its no big loss.
This was done on my 2000 TJ your application may be different.
Before I get into this please ensure that the components you choose are rated for over the max pressures and temps that you will use. Compressed air even at 150 or less psi can be very dangerous and cause serious injury or death. I take no responsibility for what you do. This is meant for informational purposes.
3/8th air line. I used high temp 300psi max pressure line form Home depot. You can get it by the ft at Home Depot length will depend on how you choose to set your system up and if you run a tank or not. I used a total of about 8 ft for my setup.
filter/ moisture seperator. This is important it will seperate the oil from the compressed air and allow you to keep the compressor oiled. I reccomend that you get one that has a valve at the bottom of the seperator to evacuate the oil back to the compressor. I used a Husky 417-548 from Home Depot around $20.
A Tank and or a manifold. Tanks can be had for around $20 or so and the manifolds can go from a simple 3 port screw on type you can get at Lowes or Home Depot for around $5-$8. If the tank only has one port you will need to add a manifold.
Pressure switch. This is needed to engage the compressor clutch when the pressure drops to low and then disengages the cluth when the upper set pressure is reached. I got mine from Simon at Wheelers It is a QuickAir part #PS001 and allow compressor on at 80 psi and off at 115psi
Most important is the pressure relief valve/popoff. This will ensure that the system does not overpressure and will open and allow excess pressure to be released in the event that the pressure switch or compressor fail to operate correctly. They can be had from Lowes or Home Depot around $8 and are set to open around 120 psi.
Intake filter. I used a breather filter from Autozone for $9
You will also need misc fittings and some smaller line to allow oil return to the compressor intake.
So then i got started. I bled off the pressure from the AC system (you may need to have this done by a shop if you feel unsafe, they can also evacuate the system as well) the larger line is the intake (low pressure side) and the smaller line is the output (high pressure side).
I then unbolted the input line to the condensor (located at the lower passenger side of the radiator(see below).
http://www.virtualjeepclub.com/attachment.php?attachmentid=9158&stc=1&d=1168983580
You now have the compressed air side free.
Next I cut the intake side using a pipe cutter. ( look where the filter is) You can place the intake where ever you prefer and I know some put the intake inside the cab. I left it there, as I dont go flying through water. I may relocate it later.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9159&stc=1&d=1168983580
After the cut i temporarly removed the intake from the compressor to allow me to drill and tap for the oil return. Its very easy to remove just unbolt it and wiggle it. It should come right out. In the pick below of the compressor it is the line to the left.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9160&d=1168983595
For the oil return i used some line and fittings that I had around. you can find something similar at your local hardware store. I drilled and tapped the aluminum line and then inserted the fitting I used a pretty good coating of epoxy as well to ensure no leaks. I used compressed air to blow out the particles and then flushed it with alcohol to ensure no contaminants were left in the line after the drilling and tapping. Heres a pic of it reinstalled and hooked up.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9161&stc=1&d=1168983580
I also installed the filter at this point you can see the pic 3 above.
The intake side is pretty much done at this point, so we'll move on to the compressed side.
The next issue I had was to connect the pressure side to the 3/8 air line i would use for the rest of the system. I removed the pressure side for the drier located on the firewall.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9162&stc=1&d=1168983580
This left me with a connector end that I either needed to cut off and use some hose and pipe clamps, I decides to use a die and cut some threads in it. I then coated it very well with epoxy and installed a 3/8 npt adapterto it. Final looks like this.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9163&stc=1&d=1168983580
Now the rest is pretty simple. I connected the airline from the adapter to the air filter/seperator.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9164&stc=1&d=1168983580
The air line then goes to my tank which is in the back of the jeep so I ran the line through the firewall then to the tank.
In the pic below you see how I hooked up the drain to go to the intake that was mentioned earlier. With the system underpressure open the small vave at the bottom and the oil is forced back into the intake to keep the compressor lubed. I wheeled hard on Sunday and changed a beadlock tire using my impact wrench and only about an ounce or two of compressor oil was blown into the bowl. A quick turn and the oil was back in the compressor.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9165&stc=1&d=1168983580
To finish the pnuematic side of this project the air line was attached to the tank, on the tak are an auxillary valve to allow filling of the system from an alternate source such as C02 or another compressor this was done in the event that the system fails, It would allow me to still use my lockers.
BTW one charge of my 3 pound tank to 110psi allows me to operate my ARBs well over 50 times before the pressure drops to below 80 psi.On the tank is the pressure swith which I will cover in the electrical part in just a bit, a drain, and the over pressure release. From the tank I have a line going to a manifold that I pieced together from equipment i had left from an automated X-Ray inspection system that I designed for my previous company. The manifold has four pressure regulators One for each ARB, one for the system pressure gauge located on my dash(normally wide open to monitor system pressure)Thsi one can also be used if one of the other regulators fail. The final regulator is for accesories (tire inflator, Air tools, blowing up LKDTJs girlfriend, etc). If for some reason my ARB soleinoid fails I can also operate them manually from the manifold by by passing the soenoid. Heres a pic of the manafold
http://www.virtualjeepclub.com/attachment.php?attachmentid=9154&stc=1&d=1168973609
and the guage on the dash
http://www.virtualjeepclub.com/attachment.php?attachmentid=9144&d=1168966211
This was done on my 2000 TJ your application may be different.
Before I get into this please ensure that the components you choose are rated for over the max pressures and temps that you will use. Compressed air even at 150 or less psi can be very dangerous and cause serious injury or death. I take no responsibility for what you do. This is meant for informational purposes.
3/8th air line. I used high temp 300psi max pressure line form Home depot. You can get it by the ft at Home Depot length will depend on how you choose to set your system up and if you run a tank or not. I used a total of about 8 ft for my setup.
filter/ moisture seperator. This is important it will seperate the oil from the compressed air and allow you to keep the compressor oiled. I reccomend that you get one that has a valve at the bottom of the seperator to evacuate the oil back to the compressor. I used a Husky 417-548 from Home Depot around $20.
A Tank and or a manifold. Tanks can be had for around $20 or so and the manifolds can go from a simple 3 port screw on type you can get at Lowes or Home Depot for around $5-$8. If the tank only has one port you will need to add a manifold.
Pressure switch. This is needed to engage the compressor clutch when the pressure drops to low and then disengages the cluth when the upper set pressure is reached. I got mine from Simon at Wheelers It is a QuickAir part #PS001 and allow compressor on at 80 psi and off at 115psi
Most important is the pressure relief valve/popoff. This will ensure that the system does not overpressure and will open and allow excess pressure to be released in the event that the pressure switch or compressor fail to operate correctly. They can be had from Lowes or Home Depot around $8 and are set to open around 120 psi.
Intake filter. I used a breather filter from Autozone for $9
You will also need misc fittings and some smaller line to allow oil return to the compressor intake.
So then i got started. I bled off the pressure from the AC system (you may need to have this done by a shop if you feel unsafe, they can also evacuate the system as well) the larger line is the intake (low pressure side) and the smaller line is the output (high pressure side).
I then unbolted the input line to the condensor (located at the lower passenger side of the radiator(see below).
http://www.virtualjeepclub.com/attachment.php?attachmentid=9158&stc=1&d=1168983580
You now have the compressed air side free.
Next I cut the intake side using a pipe cutter. ( look where the filter is) You can place the intake where ever you prefer and I know some put the intake inside the cab. I left it there, as I dont go flying through water. I may relocate it later.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9159&stc=1&d=1168983580
After the cut i temporarly removed the intake from the compressor to allow me to drill and tap for the oil return. Its very easy to remove just unbolt it and wiggle it. It should come right out. In the pick below of the compressor it is the line to the left.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9160&d=1168983595
For the oil return i used some line and fittings that I had around. you can find something similar at your local hardware store. I drilled and tapped the aluminum line and then inserted the fitting I used a pretty good coating of epoxy as well to ensure no leaks. I used compressed air to blow out the particles and then flushed it with alcohol to ensure no contaminants were left in the line after the drilling and tapping. Heres a pic of it reinstalled and hooked up.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9161&stc=1&d=1168983580
I also installed the filter at this point you can see the pic 3 above.
The intake side is pretty much done at this point, so we'll move on to the compressed side.
The next issue I had was to connect the pressure side to the 3/8 air line i would use for the rest of the system. I removed the pressure side for the drier located on the firewall.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9162&stc=1&d=1168983580
This left me with a connector end that I either needed to cut off and use some hose and pipe clamps, I decides to use a die and cut some threads in it. I then coated it very well with epoxy and installed a 3/8 npt adapterto it. Final looks like this.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9163&stc=1&d=1168983580
Now the rest is pretty simple. I connected the airline from the adapter to the air filter/seperator.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9164&stc=1&d=1168983580
The air line then goes to my tank which is in the back of the jeep so I ran the line through the firewall then to the tank.
In the pic below you see how I hooked up the drain to go to the intake that was mentioned earlier. With the system underpressure open the small vave at the bottom and the oil is forced back into the intake to keep the compressor lubed. I wheeled hard on Sunday and changed a beadlock tire using my impact wrench and only about an ounce or two of compressor oil was blown into the bowl. A quick turn and the oil was back in the compressor.
http://www.virtualjeepclub.com/attachment.php?attachmentid=9165&stc=1&d=1168983580
To finish the pnuematic side of this project the air line was attached to the tank, on the tak are an auxillary valve to allow filling of the system from an alternate source such as C02 or another compressor this was done in the event that the system fails, It would allow me to still use my lockers.
BTW one charge of my 3 pound tank to 110psi allows me to operate my ARBs well over 50 times before the pressure drops to below 80 psi.On the tank is the pressure swith which I will cover in the electrical part in just a bit, a drain, and the over pressure release. From the tank I have a line going to a manifold that I pieced together from equipment i had left from an automated X-Ray inspection system that I designed for my previous company. The manifold has four pressure regulators One for each ARB, one for the system pressure gauge located on my dash(normally wide open to monitor system pressure)Thsi one can also be used if one of the other regulators fail. The final regulator is for accesories (tire inflator, Air tools, blowing up LKDTJs girlfriend, etc). If for some reason my ARB soleinoid fails I can also operate them manually from the manifold by by passing the soenoid. Heres a pic of the manafold
http://www.virtualjeepclub.com/attachment.php?attachmentid=9154&stc=1&d=1168973609
and the guage on the dash
http://www.virtualjeepclub.com/attachment.php?attachmentid=9144&d=1168966211