On board air with a MV-50.

[slomatt]

A while ago I hard mounted a SuperFlow MV-50 compressor behind the trim panel on the driver's side of the trunk. Today I finally got around to doing a write up if anybody is interested.

http://wwww.blankwhitepage.com/automotive/2000-toyota-4runner/on-board-air

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_2442.jpg

- Matt

[4x4mike]

Did you keep the factory relay that is in the nose of the compressor? Or did you by pass it for your dash control? Also, what pressure switch did you use. Before I went with my York I was messing around with mine and a viair switch (I think I gave it to Ken). They are the small ones and I went that route because of the size and pressure ratings. Are you concerned about heat? When I used the MV50 it would get crazy hot. I would be concerned about it in that location and lack of air flow not to mention it's proximity to other electrical components. On the topic of heat. What gague wire did you run back to the compressor? The stock little jumper cables get nice and soft from the heat just airing up some 32's to street pressure.

[troyboy162]

oh man this is a sweet mod. im interested in the heat issues as well. also a litte off topic but our red pumps are good to 75ish psi does anyone know if arb lockers can operate that low? i know thats out of there recommended range but these pumps would take a year to get into the 100 psi range for any substantial size tank.

[slomatt]

Mike,

Coincidentally I bought a York compressor several years ago but never got around to doing anything with it, it's still sitting in my garage.

I left the factory relay in place on the MV-50. The wiring is as follows.
- 30A fuse in my underhood fuse block
- 8g positive lead back to the compressor. As you mentioned the stock 14g wires get hot quickly, especially since they are so long.
- 8g lead transitions to a short section the stock 14g wires. This piece is about 6" long and short enough that there isn't enough resistance to heat up significantly. It goes through a grommet and into the compressor.
- 8g ground wire from the compressor to the chassis.
- I left the stock relay in place since it is controlled by the thermal switch in the compressor motor. I removed the power switch and wired the pressure switch and the new on/off switch in series with it.

The pressure switch has an adjustable cut-in point and a bypass valve which I'm not currently using, it was purchased at surpluscenter.com. Ideally I'd be using the bypass valve, but because of packaging and cost reasons I didn't purchase a check/relieve valve to put into the system. The pressure switch is set to engage at 70psi and disengage at 100psi.

Heat shouldn't be much of an issue because the compressor is directly in line with the cabin vent so air is continuously flowing past it anytime the fan is on or a window is open. If the compressor gets really hot I guess it could possibly melt the trim panel, but it's spaced out about 2" away so I'm not really worried about it. I considered putting the compressor under the hood, but in that location it would get really hot due to heat radiated from the engine.

troyboy162,

I think ARB lockers require about 90psi to operate. My MV-50 has no problem bringing a small tank up to 100psi, and a friend of mine has been using one to power his ARBs for a year or two with no issues. He's using a small tank made out of about 8" of 3" diameter pipe.

- Matt

[Good Times]

I like the install but fear the heat generated by the compressor. I know those get pretty darn hot so I'm wondering if it'll impact any of the factory wiring in there.

[troyboy162]

bad ass! i really want to do this now. thanks for the post!

[4x4mike]

My MV50 will pump to 100 psi. It gets hot but would power an ARB. These little compressors aren't much different than a Viair or similar. Sure they aren't sealed or 100% duty cycle like some of the other models but for locker use they get the job done. Heck one of the air ride Cadillac compressors from the old cars work.

Matt, I'm really glad I was able to stick a York in the 4runner. I had one with a 9 gallon tank on my old truck and that was one of the things I knew I was going to miss when I went with a vehicle with a smaller engine compartment and with an engine that no one made a mount for. I got my mount for a company in Oregon, it's all a tight fit but was expected.

[CJM]

The thing gets so intensely hot I wouldnt ever dare of mounting it near anything flammable tbh. Just using it to pump up my tires from 10 to 35 psi was insane the last time I used it.

[slomatt]

It seems that a few people are really concerned about heat generation. I've been using this exact compressor for years to air up the 33x12.5x15 tires I had on my ZJ and while it definitely gets hot I wouldn't say it ever got dangerously hot. The part of the compressor that gets the hottest is the cylinder head and it is spaced away from all surroundings by about 1/4" to 1/2" on each side. I appreciate the input and will keep an eye on things and report back if there are any issues.

- Matt

[4x4mike]

Sweet. I'm sure it'll work fine and the install is very clean and thought out. Kudos.

I've been wanting to use that space in my 4runner since I got it. Bruce has a large inverter in that location (my concern was the heat as well and he said it's fine. We're just worried keyboard jockeys). I was thinking about getting a door from older models and installing it there. The cargo door would look stock and it would give me a little more storage without taking up interior room.

[ZUK]

It seems that a few people are really concerned about heat generation. I've been using this exact compressor for years to air up the 33x12.5x15 tires I had on my ZJ and while it definitely gets hot I wouldn't say it ever got dangerously hot. The part of the compressor that gets the hottest is the cylinder head and it is spaced away from all surroundings by about 1/4" to 1/2" on each side. I appreciate the input and will keep an eye on things and report back if there are any issues.

- Matt


You'll probably be just fine even in that confined space.....now folks that put it under the hood and are 'pre-heating' the compressors even before use might be running into a duty cycle issue.
I keep mine mobile. I use the black bag it came in. That way, I can transfer it to another vehicle....or if I'm on a tight trail and the guy 10 rigs in front of me needs air then I can walk it up to him.
A couple things I did to mine to improve it's reliability factor. I have heard that the 4 alan bolts that secure the cylinder head are sometimes loose. Now even though my unit has performed great I decided to check them and sure enough a couple of them were almost loosey goosey. I snugged all 4 up using just basic wrist action and all is good now.
I also got rid of the metric hose coupler on the head and re-tapped the aluminum threads for 1/8 NPT and then installed a universal coupler. The "metric npt" is so close in size to the "American npt" that no drilling was needed. Just lube the NPT tap and run it in. Tap it in the VERTICAL mode....that way when the tap is backed out, gravity will allow the metal debris to fall down and not get metal inside the cylinder. Then I could connect up a higher quality blue coiled air hose that I purchased for $29 from a professional hose company. It's the same kind of hose that the CO2 guys use.
I've heard of an issue with the cheap onboard on/off switch. I haven't addressed that yet but I wonder if some re-soldering needs to be done on the switch connections. Easy enough to take off the plastic end cap and find out sometime. Another day :)
Here's the link I generated on that MV-50 http://gearinstalls.com/pepboys.htm .....also sold by Pepboys as the MF-1050.
Back when they were clearing them (in 2005) from the Checker Auto stores I was buying them for 24.95 each here in Phoenix :) Mine MV-50 still works I might add. ZUK
You can still get them from Pep Boys for $59 I think. Still a bargain.

[Seanz0rz]

i purchased mine (1050) from costco a while back. i actually purchased 2. one is still new in the box. the other i have retapped for 1/4 npt but not finished the mods on the hose, those are to come soon.

as for mounting it in my vehicle, i may someday, but now it works great as a mobile unit, and fits perfect into one of my ammo cans. i think your use of that space is great! i was thinking of putting some other equipment in that general area, since its such a waste of space back there.

[CYi5]

Clean install, there's just no way i'd ever want to squeeze mine into that tiny space. If it gets hot enough to burn your finger after airing up four tires in open airspace, I wouldn't want to risk it in there, just my opinion.

[slomatt]

4x4mike,

Thanks. I'm pretty sure it was Bruce's inverter install article that gave me the idea to use that space. The only problem you might have with the cargo door is that it would require you to remove the stock sound baffle for the cabin vent, and without that you get a lot of road noise transmission into the truck. I think a sufficiently large subwoofer would solve that issue. :)

ZUK,

The stock wiring was pretty crappy, I found a couple connections that were not properly soldered. Your recommendation to tighten down the head bolts is a great one, people should also check out the wiring. I was able to "re-tap" the air outlet by just threading in a 1/8" npt coupler, the threads were already really close to that size.

CYi5,

I understand your concern, and after looking at the space and the arrangement came to the conclusion that the worse that could happen would be the plastic trim panel or the drain hose would warp due to the heat. There's not much else in there than can get damaged, the factory wiring is on the other side of a metal divider. When I get time I'll do an experiment and air up all 4 tires from ~15psi and measure the temperature difference so I can provide real evidence.

- Matt

[4x4mike]

4x4mike,

Thanks. I'm pretty sure it was Bruce's inverter install article that gave me the idea to use that space. The only problem you might have with the cargo door is that it would require you to remove the stock sound baffle for the cabin vent, and without that you get a lot of road noise transmission into the truck. I think a sufficiently large subwoofer would solve that issue.


I didn't realize that about the baffle. I figured I would use a box in there or something so I wouldn't lose anything down there. I know people have talked about a SW but I would rather have storage space than beat bobbing bass.

[slomatt]

I'm not sure what year your 4runner is, but on mine the baffle takes up most of that space, so I had to remove it. :) I ended up fabbing up a different noise suppression system that takes less room and it's working fine.

Here's a pic of the baffle on my 2000.

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_2408.jpg

- Matt

[4x4mike]

I've got a '99. I didn't know there was that much going on back there. It's one of those project way down the road when I have time.

[slomatt]

This setup has worked great over the last 5 years. I've made a few changes to improve the system and to repair a couple small issues.

I sealed the rear hitch and made it into a ~1 gallon air tank.
http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_2859.jpg

Installed front and rear air fittings using custom delrin brackets.
http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_5696.jpg

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_5703.jpg

After a couple years of use the cheap Harbor Freight rubber air hose going to the tank failed while on a trip to Mono Lake. I replaced it with some PVC air hose which will hopefully hold up better.

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_0887.jpg

The failed air hose made it so I couldn't use the OBA to air up. To prevent this in the future I added a single air chuck and a valve directly after the compressor. This way the only critical hose is the one from the compressor to the valve, I can shut off the rest of the system if needed.

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_0888.jpg

The MV50 has seemed less efficient in the last year or so. I opened it up and found a lot of crap in the cylinder. It looks bad, but most of this was small metal shavings and there was no major scoring in the bore.

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_7624.jpg

While everything was apart I drilled and tapped the compressor output to 1/4" NPT.

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_7626.jpg

I did some porting of the head and replaced the valves with re-purposed feeler gauges. The factory valves are .004", I replaced the input valve with .004 and the output with .004.

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_7628.jpg

The stock valves were riveted in place, the new ones are held with screws and threadlocker.

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_7629.jpg

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_7630.jpg

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_7631.jpg

The piston and cylinder cleaned up well. The rubber seal was kinked from the factory, I was able to get it to seat cleanly.

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_7632.jpg

After re-building the compressor it is working much faster than it was. I'm not sure if the porting helped at all, but it seems at least as strong as it was originally.

http://www.blankwhitepage.com/gallery/albums/t4r_oba/IMG_7633.jpg

- Matt

[troyboy162]

Thanks for the updates. I think this has always been the preimier oba set up for 3rd gens

[slomatt]

Thanks for the updates. I think this has always been the preimier oba set up for 3rd gens

Thanks Troy, I hope the photos I posted have been useful to people.

- Matt

[Bob98SR5]

I ran my MV-50 for an extended period of time to air up 2 vehicles and it blew the fuse and melted the wire. This was at Pismo. So i do share a concern about overheating too.