Permanently installed air lines?

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Now that I have a compressor mounted under the hood, I'm thinking about how to run some permanent air line around the vehicle. My motivation is ultimately to be able to connect all 4 tires to the same air line so I can air them up (or down!) with a single compressor or valve connection and with a single pressure gauge. Doing this will ensure equal pressure to all four tires and should speed up both the airing up and airing down process. I've seen homemade air lines to connect all 4 tires at once, and the concept has intrigued me. However, I don't love the idea of having ~50 feet of hose to coil up and store in the Jeep. Thus, my thought to permanently run air close to the rear of the vehicle.

Running a permanent line to each corner of the jeep seems excessively complicated, but might be the best solution? There are commercial kits for JK and JL that provide all the fittings and hose needed to do this, so it is a solution some people choose. I'm thinking I'll run a manifold in the engine bay to split between the front and rear, and leave a quick connect fitting in the front of the jeep and somewhere near the rear bumper. With this approach, I'd only need to have about 8 ft of hose to connect to any tire from front or rear, and could build a pair of dual-wheel lines that let me connect front and rear to both tires at once, achieving the 4-tire dream.

I haven't seen anyone else in the group with a setup like this, so tell me why this is a stupid or bad idea. Will a vinyl or rubber flex line under the Jeep (routed where it shouldn't get snagged or pinched, of course) work? Do I need to use something like schedule 40 pipe for the front to rear run instead of a flex line? Should I route flex line through the engine bay firewall, inside the jeep, and back out the rear end instead of underneath?

[flashboiler]

I ran a line to the front bumper and have a dual tire connect line so I can do fronts and then rears. The valve stem offers significant resistance and I can air up two tires at the same time quicker than airing them up serially.

I have a samurai so reaching the rear tires isn't too bad but it's still a significant hose to coil and store. My buddy ran a quick connect under each front seat, that way the dual airline is as short as possible and with the doors closed the air connection is nice and clean. Mine stays clean on the front bumper but I've had to clean ice and snow off when snowbashing. Anywhere else on the rig the quick connect would be caked in road grime unless you covered it with something, I seem to loose valve cover caps about 25% of the time I air up so keeping track of quick connect covers would be costly. I guess you could attach them so they hang but why when under the seats is really nice.

[newracer]

While I think it definitely has a cool factor I think its a lot of work and a lot of potential maintenance and problems (leaks) for not much gain. Personally I have always used CO2 as my main way to fill tires and my on board compressor as a back up. My JKU has 33s and I can fill a tire from 10 psi to 35 psi in about 30-40 seconds with my CO2 setup. I have one lightweight hose that can easily reach each tire that fits in a small bag.

[Jim]

Evan, SynergyXJ, has such a setup.

I've considered such a setup and if I were to go that route I'd go side by side vs. front to back wheel connections.

EDIT: Side by side I mean one air connection on the passenger side for the right side tires and one connection on the driver for driver side tires.

[newracer]

flashboiler previously posted:

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Jim previously posted:

[flashboiler]

The bottom one would keep the inside of my quick connect clean but would do nothing to keep road grime and mud out of the sliding collar...

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newracer previously posted:

[newracer]

When I had a TJ my CO2 tank was on the tire carrier to save room inside. I have not decided on a permanent mount in the JKU yet.

[newracer]

If I was to do it I'd just have all hose not permanently mounted. By permanently mounting a connection at the front and rear what are you going to save? Maybe 8-10' of hose?

I'd have a connection on the compressor under the hood, that way it is fairly protected from road grime, mud, and snow. Then a hose long enough to reach either side of the engine bay. Then that hose splits into two, one long enough to reach the rear and one long enough to reach the front. I'd make it all of out of polyurethane hose.

https://www.homedepot.com/p/SPEEDWAY...9413/206728276

[Jim]

For my side-by-side filling thoughts, I've considered placing the connections either near the firewall-hood-fender corners on each side of the vehicle OR maybe place them inside the passenger cabin near the driver / passenger foot area outer body wall. I'd likely lean towards engine bay as routing is much easier. My existing engine bay air connections stay clean enough that moving to passenger compartment for reduced dust isn't needed (I cap the open end of the connector / the slides haven't gotten junked up).

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flashboiler previously posted:

[FINOCJ]

Are you considering how your compressor with work in such a situation? Although less hassle in some ways to have all the lines ready to go at once, and not have to be moving the fill hose from tire to tire.... I am not sure that my little compressor would like filling them all up at once...in other words the volume of air that it can move may mean it just takes 4 times as long to fill up all the tires? My superflow likes to get kind of hot and it does have a limited duty cycle - although its not a lot, I do try to give a minute or two off between tires as I move the fill hose and fine tune the tire pressure etc....

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FINOCJ previously posted:

[Trevor?]

I am currently running a setup like this. I have an ARB twin compressor plumbed to a quick connect fitting in each wheel well via half inch rubber air line. I then have 4x 3ft sections of air hose with clip on schrader valve fittings.

I switch on the compressor, then walk around to each wheel and install the 3 foot line. My wheels have dual valve stems, so I hook up my guage to one of the extra valve stems and I have a pressure reading unaffected by the dynamic pressure in the air lines. It can still take 15-20 or so minutes to go from 25 to 55psi, but I usually just grab a soda from the cooler and keep an eye on it. I use some 7/8 rubber table leg cap-things I grabbed from the local big box home store to keep the fittings covered when not in use.

So far, so good. It will probably spring a leak somewhere at some point, but I tried to plumb it such that I could isolate the lines and run a connector straight into the compressor if I had to. Its faster than my Viair compressor filling my smaller Xterra tires (to a lower pressure) and there is less crouching down by the wheels.

Forget about airing down that way, however. There is too much resistance in all of that air line. Its way faster and easier to use one of those gauges that extracts the valve core, or a set of staun-type deflators.

Also.... I found a set of valve stem caps with little plastic retainers so they stay attached to the valve stem when you have them off. It might seem silly, but not having a pocket full of valve caps and rubber air line caps to fumble and risk loosing makes the whole thing go smoother.