mkv

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

Curtis Mueller

mkv

Hi Curtis,

I did. It ended up being leaks in both of the front air struts, even the one I had refurbished two months or so prior.
The one had a leak internally in the bellows, they hadn't fixed it properly so they redid it and the owner of the company personally supervised. I spotted it by spraying soapy water around the aluminium near the bottom of the strut.
The other (the one that I thought initially held pressure) had a leaking top mount, so air was leaking out of the top. Difficult to diagnose, but when I removed it from the vehicle I pushed down on it and it just collapsed.

So sorry it wasn't something simple! It was just city of my struts again!

They've been in the car now for a year and they're perfect. Very happy.

Good luck!
Let me know what happens with yours, I'm curious.

Mark

Rui Rosa

My adventures with suspension:
- Both rear bags (around 200 euros new on ebay - no brand) - both were leaking. Sometimes I find the car up, sometimes down...
- Left side struct (around 840 euros new on local shop - Arnott) - after 1 month had to change it again under warranty as was leaking.
- Had some leaking on block valve that could be better tight and solved the problem no cost
- Compressor (160 euros new on ebay - no brand) - changed it yesterday because sometimes I get a warning light that VCDS pointed to block valve... so far all is ok.

Please God, let the block valve and right front struct last a few more years...

mkv

Hey Rui,

Is this on C6 or C5?
I always thought/heard that the C6 was 'fairly' reliable.

Regards
Mark

Rui Rosa

C6 from year 2005.
I'm sure never had any intervention so not so bad I think... my problem is that it lasted until comes to me

mkv

I hope you do have many more km's of reliable air suspension Rui!

I'm thinking about replacing my rear air bags sometime. Did you just get the no-name chinese ones off ebay? How does the quality look?

Mark

Rui Rosa

Thanks Mark... I hope so the same
Yes, I've bought the bags from an European seller but I'm sure they are Chinese.
When I look to the originals that have been replaced and to those new ones, the differences I find is that the new ones don't have holes

Ohh... Just remembered a little mod that I've made yesterday when installing the compressor: I've eliminated the original air intake hose and replaced it with a new one that I've connected to the rear of the engine filter case.
I've done it because the audi system, in my opinion, is stupid... they put the hose getting the needed air near the right weal?! Many dust is suck to that little filter near the compressor.
Now every time I change the engine air filter I also change the compressor filter. Always clean air and almost sure dryer

Tell me something, you get your front struts rebuild or you installed new ones?
When I was looking I've found only the chinese ones, Arnott new ones and Arnott rebuild (and Audi ones... lol to the price). I've bought the Arnott new ones because was the fastest ones I could get.

Cheers,
Rui

mkv

Hi Rui,

That mod sounds interesting. I didn't look at the condition of the compressor intake filter the last time I had the wheel arch liner off, so I should really do that.

I was very lucky in that here in South Africa we have a local specialist who rebuilds these struts with new bellows. They seem to be one of the few in the world and they are only about 30 minutes drive from my home: AIR SHOCK CENTRE
For R8000 each (550 Euro), they replaced the bellows in both of my front shocks, and tested them, cleaned them, etc.

Regards
Mark

Rui Rosa

As I've told before, this audi instalation seems to me very poor... they put that little filter on a stupid place and the suction hose on a even worst place.
I've bought a connection that I've placed on the back of the engine filter and changed the all hose to a new one. No cuts, no stupid filters, as it could and should be from factory
I've spend less than 10 euros on this mod.