Air suspension leak from where?

[zit501]

Hi Guys,

So my A6 Avant's air suspension is sinking overnight/noticeably within a few hours. Mainly the fronts, which are sinking are a similar rate. Read, both fronts are sinking at a similar rate. The rears sink a bit too, but I suspect it's more a result of the fronts sinking.

I bought the car cheap in November, because it had air suspension issues. I traced these to a blown front right strut, which wouldn't even pump up a little. It had a huge leak. I it had rebuilt by a specialist company locally. I replaced that and put in BagpipeAndy's piston ring kit in the compressor, just as a "mini service". All was then well.

Through a number of reasons, I only got the car all sorted about 3 weeks back, and have been driving it since. I've been noticing this sinking symptom for the past week only.

Whilst I was diagnosing the struts back in November/December, I pumped up each strut manually. Like I said, the front right was properly blown, but the front left held pressure and the weight of the car.

Yesterday I checked for leaks around the valve block and on the fittings to the front two struts. I found one minor one for the pump fitting onto the valve block, which was probably as a result of me moving the ferrule around which doing the manual pump ups. I cut off a small piece off the end of the pipe, reattached it with a new o-ring and a little tape, and the leak seems to be gone there. I also put a little tape and a new o-ring on the front strut fittings both on the valve block end and the strut end, since all of these connections I had open two month back. Now I can't find any leaks with soapy water..

I've also put the car on lift, then on jacking mode, then jacked it up and removed the front wheels. Then I blocked two of the vent holes on the front struts with my fingers and sprayed soapy water on the open hole. No bubbles..
I still need to try jack up the hub with the wheel off to see if I get leaks at another suspension height, but it just started raining outside.

So, since the car seems to lower itself by a similar amount on the two front corners, could this be a symptom of valve block failure? Or do I just coincidentally have leaks on both front struts?
I did try park it in lift mode overnight with jacking mode on. It still sinks.
Sinks in automatic mode too.

Help?

Thanks
Mark

[54A4Avant]

Great detAiled description and sorry to see you've got no answers so far. Why not pm bag piping Andy?

[JMac55]

Hi ZIT501.

Did you get anywhere with your sinking suspension? I have similar issue and checking to see if you found a remedy?

Cheers

AUDI 2011 C6 Allroad

[zit501]

Hi ZIT501.

Did you get anywhere with your sinking suspension? I have similar issue and checking to see if you found a remedy?

Cheers

AUDI 2011 C6 Allroad

Hi there,

This was obviously a while back, but I'm pretty sure it ended up being the other front strut which was leaking. I remember doing the obviously dead one first, then a few weeks later doing the other one. Problems sorted.

A few years later I did the rears too, since I developed a slow leak on those.