Icebum

Just wanted to find out from some of the more experienced Allroad owners and technicians about a problem that just started on my 2005 2.7T Allroad.
Winter had just started about a month ago when one morning I went to start the car and the front end was very low. Rear was normal.
After starting, the car lifted up and a walk around showed all OK height wise, and no "noise" from compressor.
This did not reoccur for a few days, but then again one morning the front end was bottomed while rear was normal.

I raised driving level to #2 position and this stopped the "leaking" overnight for about a month. But it happened last night, so that this morning the front was low, and rear looked like still on #2 height.
My question is, would leaking airbags in the front cause BOTH front bags to lower, or wouldn't normal wear cause 1 bag to go sooner than the other so that the onset would only affect 1 side first.
In other words, should I be looking at a valve body problem instead of leaking bags?
Thanks.

GTA_Driver

Both airbags will deflate if only one is leaking. If you want to test for which one, leave the car in jack mode overnight.

ezveedub

If one bag leaks, the whole front end lowers, since the other side cannot support the front end. If you look carefully when it drops overnight, one side will be lower. That's you're leaking air spring. It's advised though to replace them in pairs. Usually if one is going to leak, the other will soon too. Some have used the Arnott air springs as an alternative to the OEM air springs, since they are way cheaper and have lifetime warranty. Once your air spring starts to leak constantly, it will overrun the air suspension pump and that's when they get noisy and wear out.

E-Town

I've got a leaking front left airbag on my 05, but when mine leaks only the front left corner drops. I don't know if I've just got a slower leak or a different issue.

Icebum

Thanks for the tips and advice.
I'll set the jackmode tonight and test.

While I thought it strange that both would go down at the same time since they are on four distinct channels each with separate check valves, your answers are thought provoking and reassuring that I am not on the wrong track to suspect the bags.
I will certainly replace both sides when I do the job.

Next question: Do you all recommend replacing the shocks at the same time?
It has 100,000km on mostly poor city roads.

I like the Arnott products, and if at the end of the day no one can tell the difference, I like the price!

ezveedub

Shocks can only really be checked once you get them off the car. Obviously, if its spitting oil out of the shafts, it time for new ones. Small sweating of oil at the seal is normal though.

snwyrvr

What's the difference between an air spring and an air bag? I have replaced one of my bags a few months ago when only one side dropped now the other side has dropped but that was a month ago and after resetting the level at 2 where i usually have, it hasnt dopped again. Thanks.

GTA_Driver

Air bag and air spring are the same thing.

snwyrvr

unless you're talking mm, the front can only drop on one side. My allroad has done it twice, one side each. It is severe enuf that you don't question it, you immediately know the problem.

eugenko

Jack Mode does something also when the car is off with removed key (on A6 C6) ?

Can I exchange the front & rear lines on the valve block for a test?
I replaced both front air struts for refurbished, but the front still sinks after one night.
Could it be valve block?
No leaks identified with soapy water.

Thanks