Originally Posted by JadeRunner
Wow Bill , sounds like you were way ahead of us. I think I'll change my order to two. I like the idea of hard mounting them.
I found a couple other things of interest. The hose quick connect fitting is nonstandard, interestingly the very same as the ARB 'quick'
(yeah, right) fill kit. I tossed that so I could use my shop standard. You can use barb fittings to adapt 1/8" NPT fittings to the fill hose if you like the fill hose/deflator arrangement (works pretty well). I used the pressure gauge on a Tee fitting in the fill line to see the tire pressure (they are pretty accurate, if a little light on resolution - 5 lb. increments), and left another on a Tee hardmounted to see the system pressure. I then put a 1/8" NPT ball valve so I could shut off the fill and read the tire pressure without disconnecting anything else.
Some of the fittings on the compressor are 1/4" NPT and pretty painless to adapt to hardmounted lines. Some are not; they are pretty close to 1/8" NPT but not quite (I think they are not NPT, but straight threads, with the fittings held in place via red Locktite). I prefer the sealing qualities of tapered threads, so I forced- um, let me say, 'persuaded' 1.8" NPT fittings onto / into these fittings. Examples would be, the output port, and the pressure gauge male end/ gauge female port (which is functionally the same as the output port, I took the head off - O-ring gasket - and examined it, so you can have a side output if that suits you better).
If you are not into forcing things, picking up an 1/8" and 1/4" NPT tap set is the solution, but not really needed. Threadlocker is. You might need a tap for a bumper 'air tank' if you do what I did, using a rubber air hose and threaded barb fitting to fit it.
I think the part number for the rubber isolators is 17853-35010, a rubber bushing with 8mm studs protruding both sides. You will need some nylock nuts for these (cheaper almost anywhere but Toyota). Pop out the rubber feet from the air compressor and replace with these. Don't hold me to it, but I do think that's it.
Oh, I almost forgot. Be sure to test the compressor before hardmounting it. I had one that decided to not work after I mounted it, this enabled me to discover that one compressor under the hood is a little susceptible to thermal shutdown...
I unmounted it, disassembled it, and fixed an intermittent on the on/off switch. Oh, and I left the switches in place for selective shutdown if needed for whatever reason. You could elect to remove them.
Use a fatter gauge wire than what comes with the compressors, and you will have less voltage drop. CarQuest carries the appropriate relays (12V, 30A) and bases (I think a headlight socket, actually!) for the relays. Radio Shack carries just the relays. They are available elsewhere on a hit-and-miss basis.