A few months ago I decided I wanted on-board air for my pickup. After a bunch of research I decided against an electric compressor and to convert the A/C compressor I had to an air pump. Most of the information I found on how to do this was scattered widely all over the internet, so I thought I would collect it all in one place. Here are some key points:
-- Compressed air stores lots of energy, and accidents can turn ugly. Make sure the components you use are up to the pressure you will be applying, plus a nice fat safety factor.
-- Unless you luck into a York compressor, A/C compressors need oil. This is well known, but bears repeating.
-- The input and output on the Toyota A/C compressor are standard flare fittings. At least they were on this one, 5/8 on the input and 1/2 on the output I believe.
-- If you just want to air up tires, you don't need a tank. I want to run air tools as well, so I added a five gallon tank.
-- If you are lucky, you can get most of what you need at your local scrap yard.
Stick around to the end for a souper duper air filter!
First we mount the AC compressor on the engine. Mine came with a mounting bracket, and I used some very temporary spacers to get the pulley lined up.
Getting the right oiler was a bit of a challenge since the input to this compressor is a pretty low-flow system. I finally settled on the Arrow Pneumatics L354W because it is designed for such systems. Here it is on the compressor with a filter to catch incoming grit:
I ran the output past the front frame member and above the skid plate to the opposite fender well where a water/oil separator and the pressure switch were mounted. The union is necessary to give the tubing freedom to get around all the corners involved. (skid plate removed for clarity)
This is the separator (Arrow Pneumatics F554W) and a Square D Pumptrol pressure switch. The switch is adjustable from 100-200 PSI shutoff. The safety valve is set at 200 PSI.
I ran soft copper tubing throughout the whole system. I got it as scrap at my scrap yard so it was cheaper than new hose, plus it may hold up better. This runs along the driver's side frame to a tee. From there one branch goes to the pressure regulator and output, and the other to an air tank on the driver's side at the back.
Here's the air tank:
And the box to house the regulator and output:
I know, there are holes in the front of the box. Those will be covered up soon.
I debated about what to do for an air filter. Most air filters I could find cost $$$ and open air filters are known to get dirty faster than I like. So I decided to make a souper duper soup can air filter. I drilled a hole in the bottom of a soup can and soldered a pipe into it, protruding into the bottom of the can about an inch or less. Then I stuffed oily rags made of tightly woven cloth into the can and made a bracket to hold them.
I'm going to do some formal tests on the soup can filter soon. If it passes it gets to stay, otherwise it will be swapped out for something more conventional.
