Good morning, while it's not that cold today, we have had a few very cold days here in Canada.
I have a 2004 with SLS. When I got the truck, I was planning on replacing the bags as they looked weathered (I also have an Audi Allroad, the old type so I know about bad bags...). First sign of cold weather this fall and the Dicso sagged. I immediately installed two new Arnott airbags.
Well when it's -10C and under (14F and below), it still leaks out, quite rapidly too, over a few hours I see a definite sag, mainly on the left side, and then it will go down both sides overnight.
It's a bit hard to spray soapy water on the hose connections when it's that cold outside making diagnostic harder... Is there any other part of the system that is prone to leaking when very cold? No leak at all in my garage or on warm days.
Thanks for any help!
Cheers
David

 

Unfortunately all of the components in the system are prone to failure. I'd convert it coils.

 

Since you have already replaced the bags, fixing the rest shouldn't cost much more cash.

If they inflate but leak over time then it's either the lines, the connections at the bags or at the valves, or the valve ***'y itself. Lines and fittings are cheap and the Ebay valves are around $100.

There are also kits that allow you to attach schrader valves to the lines so you can manually fill the bags with shop air if you loose a compressor.

 

I am really hoping to retain the SLS. I am a fan of them for air ride quality in loaded and unloaded condition. I have 4 kids so when we are the whole family, some gear and a small trailer, having no sag is great!
Interesting about the Schrader valves. I will try to use warm soapy water or maybe antifreeze and soap solution for diagnostic in cold weather. The bags came with new fittings but I loosened up the one on the valve block for the left side to empty the bag so that one might need to be lubricated a bit. Hopefully it's not much.
Cheers
David

 

If the bags are new I'd check the valves next. They're a moving part & they fail. The lines can leak, but it'll be seals as the lines themselves aren't a moving part.

 

Mine does the same thing when it drops below 0° F. I replaced the bags a few years back when it did it the first time, but the new bags do it also. My solution has been to park it inside and drive something else when it's really cold.

 

Not the best option for me, I could park it inside but since it's that cold most of the time here, I want it to be good to go.
It's cold again today and it is half down already. I took the bus this morning but I hate to see its *** sagging when I get home... I will start it up, inflate the bags and try to find the leak in the cold today! there are not that many components and I am pretty confident it leaks on the left side so I should manage to find it. Unless it's an internal leak in the valve block, then it might be harder to diagnose, perhaps I can hear it with a mechanic stethoscope.
(other car is a 2002 Audi allroad... 4 bags, all new, at least they don't leak anymore, it has other problems though...)

 

Hi

I have had my 2003 D2 TD5 from new and never experienced any sagging of the SLS air suspension in all/any weathers. Might I suggest your problem is either a faulty connection to the air bags or the SLS system is defective and not maintaining pressure at the levelled given height.

 

I went out in the much cold yesterday morning (-17C I think) and found the connector for the line going to the left bag on the valve block to be leaking if I touched it. I will try unplugging the voss connector, greasing the line with o'ring grease (it says it ''lightly swells the o'ring for better sealing'') and reassemble. If that does not cure it, a new voss connector should! Hopefully it's that easy!