310 on board air system

[mayco]

Im waiting on delivery of new parts to rebuild my on board air system. Ill be using a relay and pressure switch. Power to the compressor will be direct to the battery with an inline fuse. Which battery system would you folks suggest for the compressor, house or chassis? Does it really matter on the diesel? All three LOOK like they are tied together however I thought I had read that their charging systems are supposed to be converter for the house and alternator for the chassis. (I admit Ive never put a meter on it to test)
I would like to tie it to the house batteries but am I risking discharging them while on the road? Max draw on the new compressor is 26amps. The current ignition circuit will just activate the relay only. Thanks for your input.....

VIAIR Corporation - 400C Compressor (P/N 40040)

Mike

[dadstoy]

I have my compressor connected to the engine battery.


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[Smartstream]

I agree with Dadstoy, the air system is a function of driving and should be powered by that battery. I've had a Viair pump for several years now and it has been flawless.

[mayco]

Thats what Ill do then.

[PeterH-350LE]

If the Isolator is hooked up and working as intended, it would not matter which 12V circuit the compressor is hooked up to.
But if you hook it up directly to the motor engine, by passing the ignition, you may have some unpleasant wake up calls in the middle of the night or find a dead battery after that extended hike.
Whichever battery you choose, I would run it through an ignition activated relay as intended.

[mayco]

Yup, Im using the original ignition circuit to activate the relay. Only the compressor will be powered by the fused line going directly to the battery.

[idroba]

When I had my 310, I did exactly what you are doing and connected the relay power input to the engine battery. I finally had a very tight system and so it only ran occasionally anyway.

[mayco]

Exactly Idroba. I am going to add a quick coupler also.

[cmadmaxman]

Your on the right track. I also put in a new aluminum tank. I run a fused 6 gauge line back from the house bank relay powered by the old ignition line, and a re-setting 30 amp relay at the compressor. I put in a new pressure switch to comes on at 90 and off at 105. Good luck on your project.

Old tank

New tank

New compressor right at home!

[mayco]

I hate plumbing.........just sayin

[mayco]

Got the new compressor all installed this morning. The original setup had two air lines from the tank, one supply and one return to the pressure switch. Surprise, I need to spend more time reading the 310 manual , it showed the setup.
The compressor sits in the rear compartment street side in a small space also occupied by the transfer sw. I had about 6" of width to get the compressor in . So, I had to plumb the compressor up and over from the exhaust port so as not to make it wider. Added a quick coupler and a shut off valve to the bags. The pressure switch/relay combo from Viair is a space saver and works great .
The compressor that I took out looked more like an aquarium device than for truck suspension.
The Viair 400c took it from 0psi to 105psi in a little over 4 minutes. It specs at somewhere around 2.5cfm. Nice to do the tighten up on that whole system!!!
Please refrain from laughing too much at my plumbing......did I mention that I hate plumbing.



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[idroba]

Originally Posted by mayco

Got the new compressor all installed this morning. The original setup had two air lines from the tank, one supply and one return to the pressure switch.

On the original system there was a check valve up near the tank. The second line from the tank back to the pressure switch was to allow the switch to read the tank pressure only, after the air went through the check valve. That hidden valve caused me no end of grief to find and change. Mine was stuck shut and virtually no air would flow from the compressor to the tank. Why the check valve and why the location? Somewhat of a mystery but that is how mine was factory built. So, I hope you re plumbed with the same specific line from the tank to the pressure switch, otherwise your switch will not read the tank pressure (assuming your check valve is working).

One of the main reasons I got my 310 for so little money was most likely the fact that the rear air suspension was way screwed up and no one understood how it worked or how to repair it. Once I got it going it would hold air for very long periods of time when sitting, in fact all winter. As I recall, on the road it added air about each 1000 miles. A good system thus does not run very often.

[mayco]

EXACTLY! Yes, I found that check valve after I had everything back together and installed. I was scratchin my head. All the compressor would do is fill the line and then cut off. It didnt look like a check valve, more like an adapter fitting or something. I was able to track it down pretty quick though, nothing seems straight ahead on these beasts. Replaced the top port fitting also. Shes running good now though, I think all the leaks are gone. I used my phones stop watch just for fun, to time how long it takes to fill the system. From 0 to 105 in 3:30

[dadstoy]

Good job! It's nice to have a tight air system. I redid mine a few years back and it works great. I'm a bit concerned with all the weight of the hard plumbing attached to your compressor head. Are you going to support it somehow? I also installed a quick disconnect in one of my storage bins for an air hose.


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[mayco]

I didnt even consider that, the weight of those fittings and pipe. They will take a beating for sure with road vibration. Ill look at that. I mounted the whole compressor on a piece of treated 1x6 so it can slide out all in one piece. Would hate to damage the exhaust port on the compressor head. Maybe something mounted from the bottom up rather than top down.

[cmadmaxman]

Hey Mayco, I only used the line & check valve that came with the compressor coming off the compressor outlet and, check valve at the end at the tank. I used a simple non adjustable switch that controls the relay. Take a look at my drop box to see my complete air line set up for the rig for some ideas.

Air tank & Compressor

[mayco]

Thanks maxman, I did the same. Only one check valve and one air line leading to the tank. Used Viairs 85-105 pressure sw relay combo, non adjustable that Im aware of. I did have the check valve located in the wrong spot when I first put it together, in my system it needed to be the first fitting off the compressor. It seems to be working well. Its been just to cold here to get underneath and do a thorough leak test on all the junctions. Its bleeding down after about 3 days so Ive got a small leak somewhere. But its pretty much good to go as it is.

[mayco]

Yours looks like a very nice and clean install. On my 310 the transfer switch is located on the right side of that little compartment with the compressor so it didnt leave me much room in there for the compressor. I still need to get in there and get some wire ties on to clean it up a bit.