only disadvantage to having on-board air is all the new
friends you aquire at the end of a run. Suddenly your popularity
quotient increases dramatically.
Selecting a Compressor
I considered a York piston compressor with it's seperate
oil reservoir, but couldn't find one with the serpentine
pulley. They are also larger and don't really offer any
benefits over the rotaries (see footnote). I found a stock
Sankyo rotary compressor from a Jeep and decided that it
could easily replace the existing idler pulley. This compressor
was off the shelf in a Kansas junk yard so it didn't come
with any mounting brackets. The factory mounting brackets
require the use of a different belt for the A/C setup. Since
I carry a spare serpentine belt and didn't want to replace
two relatively expensive belts I made brackets that use
the non-A/C belts.
you lay out the cash for the compressor connect a battery
and make certain the electro-magnetic clutch works. While
the clutch is engaged spin the compressor and see if you
can feel suction and/or pressure through the ports.
Sorry, I didn't take any pictures of the brackets, but they
are just two pieces of angle iron 1.5 x 2 x 8 inches long.
The hardest part was getting the compressor with a 5 inch
pully to replace a 4 inch idler and maintain the same belt
The main reason for choosing this particular pressure switch
was because it has four 1/4" NPT ports and becomes
a compact manifold that all the other parts screw into.
This switch will start the compressor when the pressure
is less than 90 PSI and turn it off at 125 PSI by cycling
the magnetic clutch on the A/C compressor.
The parts in the list below came from Grainger
equipment and supplies.
For some reason (heat, vibration or oil) the polycarbonate
bowl has cracked on three different oil separators. I have
since discarded them and am looking for a small industrial
grade oil separator.
I also replaced the inline check valve with a more positive
check valve triggered by the pressure switch instead of
the input/output pressure bias. The picture doesn't quite
match up to the components now.