Schrader Valve installed in Suspension Air Tank

[bbyer]

This mod is part of my ongoing quest to reduce the probability of going down to the stops and remaining there until I can get the 3 to a Dealer.

Like Australia, the distances here can be in the hundreds of kilometres – even thousands if you are going the wrong direction – in my case north, as the nearest dealer north of Edmonton is in either in Iceland or Greenland.

I removed the bung, (shown in fuzzy picture below), from the front of the air tank and installed a Schrader valve. This was possible as my 3 is a 2005 model where the air tank has an unused outlet at the front of the tank which is located just above and behind the left front wheel well. The unused bung is also on tanks in the 2006 models and some 2007 units.

The exploded view picture shows the components I needed for the mod. The significance of the air valve is that the valve is the type used in aircraft struts, (oleos). The valve is rated at 2000 psig, (140 bar), whereas a normal vehicle valve is rated at 200 psig, (14 bar), with peaks to 300 psig, (20 bar).

The reason for the AN/MIL spec valve is that the air tank has a normal working pressure of about 244 psig, (16.8 bar), and the relief/exhaust valve is set at about 350 psig, (25 bar).

My intent is to use the Schrader valve as a fill only, (not air off), as I regard the normal +200 psi working pressure of the tank as too dangerous for routine use. Also, even if the pressure was reduced with a regulator, the air is I regard too “high class” for filling say tyres. The air is both dry and dust free, the job of the dryer and filter within the units – not something I wish to tax any more than necessary. I might add that others disagree.

I note that I had a recent compressor only, failure. The air suspension computer still wanted to lift the 3 as usual, however since there was no air available in the tank, there was no lift. What this meant was that the electronics controlling the air spring valves did not require air in the tank for them to operate, however no air available meant no upward movement.

The Schrader valve into the air tank is hence one of my approaches to be able to inject air into the system – in other words, do the job of the compressor. What I also discovered is that once the 3 is up at normal height, if one does not play with the suspension control, the 3 will stay at normal driving elevation and not self lower – except maybe at night, (auto level wakeup), and the solution there is to disconnect the battery.

I say this as realistically, about all one will get into the tank with a shop compressor or portable, is air at about 150 psig, (10 bar), enough to lift the 3, but leaving nothing to play around with.

[gghaggis]

I find it better to splice into the system just after the cross-link valving, one for each air-bag. You have to then air up each bag individually, but a reasonable portable air compressor can manage it, and it removes more points of failure from the chain. I made up a little kit to do this on my D3.

Cheers,

Gordon

[bbyer]

Actually what you are saying you already have done is my yet to be implemented, plan A. The air tank Schrader valve mod is plan B.

Teeing individually into each of the four air springs is really the proper solution as it does eliminate, as you say, "more points of failure in the chain". Regardless of whether the fault is the compressor, the computer, or the wiring, you still are able to lift the 3 and the air pressure required is probably less than 100 psig, (7 bar).

Re my version of plan A, the trouble is with the fittings I propose to use to T into each of the four air springs just down stream of the respective block valves.

I decided that I did not want to actually cut the Land Rover factory 6mm air lines, but got the idea that if I could purchase four Voss System 203 Tee connectors, part number 5 2 03 09 51 00, per the attached Voss catalog pdf, then I would not have to actually cut the Land Rover air lines.

Well that is not so easy - that is purchasing the Tee's. I have not yet been successful in getting Voss to respond to my request as to who actually sells the System 203 fittings.

I have found some heavy truck repair outfits that sell the Voss System 230, 232, and 240 fittings, but not 203.

Until I resolve the sourcing of the Tee's, my plan B is all that I have been able to implement to date. Getting Voss to respond is the current challenge.

I noticed your comment regarding "little kit", and I wondered what that entailed.

[stevo]

there are company's in aussie that sell those type of air fittings I bought some to do the mods on my DII to slow the down movement on the suspension.

Suprised you cannot get anything from the USA??

[bbyer]

I just took your suggestion and sent an email off to General Pneumatics http://www.generalpneumatics.com.au in Mordialloc Victoria. They do not have anything on their web site re Voss, however they do carry a line of DOT push fit metric fittings so that is a good start.

I think the reason I can find very little here in either Canada or USA re Voss is that metric is not very common here.

I expect metric and everything else is much more the norm in Australia as you probably have a greater variety of manufactured products arriving from everywhere that what we have in North America.

I expect you are all experts on Metric, SAE, British, and even more fun, Japanese fittings and threads. If you have an suggestions as to possible contacts re Voss product, I would like to email them.

[gghaggis]

If you have an suggestions as to possible contacts re Voss product, I would like to email them.

I can't remember their name, but when I'm next in the store where I got mine, I'll pass on their contact details to you.

Cheers,

Gordon

[CaverD3]

The Voss fittings are strangly imperial threads.

I think the easiest way would be just to cut the lines and put in a T piece quick connect. This is how we install the suspension lift (Air-Up) system for MY09 and above.
Once the T piece is in you would need a valve to attach so you can close it when you have filled the bags.

Maybe just have the bits in the glove box and only cut and install in an emergency.

[bbyer]

Yes, I agree, the Voss fittings are very different from anything else I have seen. I purchased a couple of the straight connectors from Land Rover just to get a good look at them.

Cutting into the Land Rover lines is I agree the most practical way of putting a T into the line.

At the moment, I am still trying for what I call the more elegant solution - the Voss tees, but will we see.

I can get DOT 6mm push fit T fittings from Parker locally - well, they order them in from I guess the States. Re Oz, General Pneumatics - per attached, have a good selection of metric / SAE combos and the DOT fittings have the internal tube support even though the brochure does not make that clear. For you guys, that ready availability can be useful.

At the far end of the tube, I planned on installing a Schrader valve. The plan is to bring all four ends into the engine compartment. I already have the 6mm air lines run, the hold up for now is the T fittings, Voss or otherwise - hence the Plan B, for the immediate time, as a result of knowing what the fitting size was going into the air tank, (thank you), so I could find the correct adapters before I removed the existing bung.

[Blknight.aus]

skip the VOSS stuff, festo, wabco and bendix make exactly what you need to T in the way that you want to.

you might want to consider the Y or parallel joiners if you're going to route the hoses anywhere because they let you anchor the hoses to each other and they take up a lot less space.

I can get pics of the pieces I mean from the gear at work next week if you like.

[Graeme]

A T wont be of any use if a corner valve is stuck open.