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Discussion Starter #1
Does anyone know what the compressed air fittings are on a 2005 square-cab mog please? (Pic below)

I want to arrange a low-pressure airline take-off point, but none of my local engineering suppliers have any idea what the vehicle fitting is, or how it works. The Mercedes main dealer couldn't tell me either.

Surely this must be a standard thing? It's pointless to fit a separate electric compressor when there's plentiful high-pressure, dry, air on board already. I assume all it needs is the right adapter to convert the existing take-off point to a standard compressed air tool fitting, via some kind of pressure reducer.

Has anyone else done this?

Thanks, Mark
 

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Voss 232, I'm not sure what size, but it should be in the UGN bodybuilder manual. Also advice on where to get air for auxiliary purposes. Too big to upload.
Unicat took air off my system installing fording air pressurization for generator box and gearboxes.
Maybe you could PM me your email address?

http://www.voss.de/files/auto_400_downloads/katalog_voss_stecksystem_232.pdf
Charlie
 

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You can buy an airline that fits those fittings, chop the other end and fit a standard adaptor to it. Getting to the spot to screw in the hose is a hassle so I wanted to add a half metre hose. Drilled out the white valve and fitted a female threaded connector with a short lead with quick-connect fitting to suit my air hose. A rubber boot for a chair leg makes the perfect dust cap.
 

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Discussion Starter #4 (Edited)
You can buy an airline that fits those fittings, chop the other end and fit a standard adaptor to it. ...
Voss 232, ... Unicat took air off my system installing fording air pressurization for generator box ...
http://www.voss.de/files/auto_400_downloads/katalog_voss_stecksystem_232.pdf
Charlie
Brilliant help, thanks gentlemen.

I'll do some research about where to order these Voss fittings. Neither I, nor any local engineering supplier in the UK, had heard of or recognised them.

One thing I don't understand though (I'm new to vehicle air brakes) is isn't the on-board air at a very high pressure (18.3 Bar), unsuitable to take off directly to normal air tool hose? Of does the Voss 'test point' (that's what it's called) include some kind of pressure limiter?
 

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Discussion Starter #5 (Edited)
Oops! as Charlie said, it’s all in the BBM. Here are the extracts for the guidance of others who might be searching for this information.

Factory option code Y31 would provide exactly what I (and probably most users on here) would want: an ‘auxiliary consumer connection.’

But the manual also states: ‘… air can also be tapped for bodies and equipment at the auxiliary consumer distributor installed as standard’:

4.4.6.3 Tapping air at the auxiliary consumer distributor (standard equipment)
Every UNIMOG vehicle is equipped with an auxiliary consumer distributor as standard. This distributor is located in the area of the 3rd frame crossmember on the left-hand side of the frame and is supplied by connection 24 of the 4-circuit protection valve i.e. an air pressure of 8.30 - 0.20 bar is available here.

Free connections are sealed with an appropriate plug (part no.: A000 998 42 50). Once the plug is removed, a compressed air line with a suitable connector can be connected.

In order to disassemble installed connector components, the retaining screw M16x1.5 screwed into the auxiliary consumer distributor must be removed together with the inserted part and replaced with a new retaining screw (part no.: A000 997 47 34).

The vehicle is equipped with the connector system of Voss, series SV232, NG8, on the auxiliary consumer distributor.

Part numbers of suitable connectors for various line diameters are listed on the following (See pics below.)

Voss parts to extract air from the standard distributor also have Mercedes parts numbers, which makes it easy (if no doubt more expensive!) to order these few bits.
 

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Discussion Starter #6
OK, so I found the 'auxiliary consumer distributor' (pic below).

But guess what? All four aux take-offs are already occupied from the factory. Mercedes makes a big deal about providing aux air connectors on all Unimogs, but then use them all themselves. Analogous to when I buy my girlfriend chocolates, then help her by eating them all :smile

So I'll need to find somewhere else either at, or downstream of, connection 24 of the 4-circuit protection valve. (This line supplies the aux consumer distributor).

The problem is, there's a mass of wiring and black tubing, all of which looks the same and is impossible to follow accurately. Does anyone know where the '4-circuit protection valve' is and what it looks like please?
 

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Install a tee fitting between one of the aux connectors and the distribution block. If they are connected with banjos, get a double banjo bolt and a second fitting.

You can then run that to your own distribution block, depending on what you're using it for. The plastic cap with the press fitting is likely a test port and might not be behind the protection valve.


OK, so I found the 'auxiliary consumer distributor' (pic below).

But guess what? All four aux take-offs are already occupied from the factory. Mercedes makes a big deal about providing aux air connectors on all Unimogs, but then use them all themselves. Analogous to when I buy my girlfriend chocolates, then help her by eating them all :smile

So I'll need to find somewhere else either at, or downstream of, connection 24 of the 4-circuit protection valve. (This line supplies the aux consumer distributor).

The problem is, there's a mass of wiring and black tubing, all of which looks the same and is impossible to follow accurately. Does anyone know where the '4-circuit protection valve' is and what it looks like please?
 

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Hi - great job on your truck- beautiful
Work .
Regarding tapping your air system,
Here is what I think :
I believe that you already have at least one air tap , possibly two,
But you may have not found them yet.( I could be all wet...)

I'd suggest looking in and around your air tanks, and all of the piping between your tanks and the regulators. The taps have a rubber cap, and they can blend in pretty well.

I have photos of a U5023 that I spent time with ( cannot post photos
At the moment ) , and the air taps are right on the rear air tanks. Pull, the cap, put the factory aux. air hose
On it (BW surplus), and air up your tires, etc.
I will post photos when I can.
Also , you can tap the system at the
Tanks, and if you have 'Glad Hands'
For trailering, you can use a trailer side fitting on the Red glad hand and tap the air, without taking anything apart. ( you just put the trailer side piece on the end of your hose and plug it into the Glad Hand-
For temporary use.)
There is a thread on here somewhere that shows a variety of air taps that owners have installed.
Still, I'll bet you a beer that you already have at least one, just waiting to be found. I would not
Take anything apart until I had done a good look .
 

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Correction -" ON and around your tanks " - not in them. Ahem.
Yes - your first photo is indeed the little gem you seek. Like I say, they can blend in pretty well.
 

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I have been looking at UHN photos,
And some UHN's have two air tanks at the Rear, and some ( like yours, I think) have the air tank(s)
On the right side. In photos I have looked at, the lower air tank on the right side has an air tap.
 

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Also- on your left frame side, you may have a usable tap as described
In the Builder's Manual -4.4.6.2.

This would be the forward tap, on the small 'air can' " Above the master Brake cylinder ".
This one has an 'F' stamped into the sheetmetal holder and would provide usable air.

The rearward 'air can' has a matching fitting, but is not OK to tap into for an air supply, as it is a Brake Test Connection.
It appears that your truck has these fittings as described in the manual.
 

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Discussion Starter #14 (Edited)
Hi - great job on your truck- beautiful work.
Regarding tapping your air system ...
Hey, Truktor, thanks for the compliment and all your very helpful information, which I've only just seen. (I've been distracted fixing my house and building other things which don't move - ie another garage :smile )

My U3000 does indeed have loads of little 'test points' all over the place, but the problem is I have no idea which are unregulated mega-high pressure and which are more sensible. There is no factory-fit accessory air option, and all the test points I have correlated with the bodybuilders' manual are just that, 'test points', which, as you say, can't be used as take-offs.

I'm now trying to get the camper at least part-finished before the end of the of the school Summer holidays so we can have a test run, so I'm probably going to give up, take the truck to a Unimog specialist and say, "Fit a compressed air take-off please", then walk away. :smile

Paying a bill for something that simple will irritate me, but time is finite. Once it's done, I'll post pictures here to help others in the future.
 

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After spending a lot of time on it, I have sourced some of the air fittings as VOSS catalogue 20. For example, the Tee fitting at the receivers on my vehicle are: 22mm x 18mm x 12mm and is VOSS part 08 53 09 20 70. The Mercedes part for it seems to be: A001 997 95 72.
I note that the same VOSS catalogue also has the air drain valves and the test point fittings.
I will be buying from VOSS in Europe most likely, as no stock in Australia.
 

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I have this same fitting on my L1116 truck and I was working on getting air out of it today and noticed this thread! I was wanting a quick disconnect so here is what I did:

IMG_1612_1.jpg

I found these Dorman 800-078 M16 to M10 fuel line adapters at the part store. The adapter diameter is too large to engage the tip on the truck, so I used a 4mm washer and a 7/16" x 3/32" HNBR O-ring.

IMG_1613.jpg

The washer OD is around 9 mm or so and the O-ring centers it in the adapter. Perhaps a M4x15 washer would be better.

IMG_1615.jpg

On the other end I used a standard barb to 1/4" NPT fitting to go into the quick disconnect. The hose is 10mm coated polyamide tubing from Belmetric, but 3/8" air hose would work as well.

So I hope this helps you guys find something that works.

enjoy.

Wengejor
 
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