I wanted to post this idea to see if anyone has tried it before-

Mount your tire inflation air compressor under the vehicle in the spare tire storage location. (Obviously only if you are running tires too large to use that location anymore). Run the plumbing and gauge up to the rear of the vehicle and install it by the 12v socket. You would have to find a good route for the cables to the battery and fab up some armor to protect it but....

My main concern would be trapping heat from running the compressor and water crossings. What are the other reasons this is a bad idea?

Thanks,
Eric
07 LR3 SE 4.4

 

That's where I would try to mount a compressor if I didn't have my spare tire in that spot. I don't think I'd worry about trapping heat since many people seem to mount their compressor under the hood and them seem to survive. That area would be significantly cooler than under the hood.

Water crossings are another story. You may have to look for a compressor that's IP68 rated, though I honestly don't know if you'd find one that is. Of course, you could also just pick up something like a Masterflow MF-1050 with a coupon from PepBoys for $42, and if it bites the dust, then lesson learned (and a relatively cheap/easy lesson).

As far as running wire to that location, I've actually done it for solar charging. You basically take the wire from the battery, through the firewall on the driver's side and down the driver's side length of the car. Once you get in the trunk, you'd come through the driver's side tail light (in the same way as the tow electrics) and down under the car. If you take the rear bumper off (not too hard), then you can keep the wire up high and run it over to the center of the car, then bring it into the spare wheel well.

 

I was thinking of using a Masterflow unit for this experiment. It's hard for me to justify the cost of an ARB when you could buy 6 or more Masterflows for the same price.

I will look to see if there are any IP68 rated units out there. Maybe marine units?

Thanks for the info on running the wires. Greatly appreciated.

 

Well, the way I see it, there are two hurdles to overcome with regards to the compressor being underwater. The first is the electrical problems. Probably not a whole lot you can do in that regard except seal up what you can with silicone caulk. At least there is no circuit board or anything to deal with... just an electric motor.

The second problem is the air intake. You don't want water to get into the air intake hose/port and get inside the compressor. The LR3 EAS compressor overcomes this by running it's fresh air supply hose up and into the cabin I believe. I think the intake is actually in the trunk near where the rear A/C unit is located. I wonder if you could do the same with the MF-1050. The air intake for the MF-1050 is just a threaded hole where you then screw on an air filter when you're ready to use it. If you just skip the air filter at this point, you could screw in a hose connector and then run some hose up and into the same area that the EAS compressor uses. Then, you could put an air filter on the end of the line.

This might all be more trouble that it's worth, but would be pretty sweet if it all worked.

 

Assuming you aren't running a second battery, I recommend putting the compressor above the master cylinder in the empty box sitting there. I currently have a Viair Dual 400 there and love it. To heck with ARB - this setup is cheaper and puts out more air and has never let me down. It's supposed to be rated 30% duty cycle but I've aired up 10 tires straight before it got too hot and shut one compressor off (it came back after cooling).

This is high and dry, so no worries about water ingress. Plus it's only about 5' of wire from the battery instead of 15' or so to the back of the rig. Given this setup uses about 60 amps, I'd prefer not to run it a long way even though I already have a 6 ga wire run to the driver's rear for future expansion.

 

A second battery is in the works. The LR3 is just too dependent on electricity for me to feel comfortable on a single battery. I plan on routing the air compressor, winch, off road lights, CB (maybe) to the second battery. I am unsure if I will set it up to charge a trailer's battery though. I go back and forth on that.

Something that cmb6s (no idea if you can tag people on here) said that made me think- The EAS compressor is sitting at the same level as the spare tire and that is below the water depth maximum. The air breather makes perfect sense but I don't think there is anything that is that special about the compressor and it survives. Any ideas as to why? I have looked for IP68 compressors but so far I have come up empty.

 

I don't know what, if anything, makes the EAS compressor special, but I would guess that it's not IP68 rated either. Perhaps IP67 is good enough... it looks like some of the VIAIR compressors are IP67 rated. Or, maybe you don't even need that rating. I mean, technically, the EAS compressor has to actually operate underwater, but whatever compressor you use to fill tires will never be operating while submerged. You just need to prevent it from getting damaged by taking water into the cylinder.

Focus on solving the air intake issue, and I bet you'll probably be fine. Of course, you could always test your compressor by submerging it in a bucket for a 30 seconds or so, then taking it out, letting it dry a bit, and firing it up.

 

I'll put this together and see how it goes. I'll start with a basic Masterflow unit in case it all goes south.

 

Mine lives in the cubby on the driver's side of the boot.

 

I have considered that spot as well and it will probably be where it goes if the spare tire area does not pan out. What unit are you using?