audi/vw suspension help needed

[HMP]

Curious if any others here have dealt with the air suspension that came on the Allroad or other VW/Audi cars.

Got an issue on the gf's 05 allroad, things were fine until Friday when the front just quit building pressure, both sides.

The compressor is working, rear will start to lift up, but nothing up front.

I was hoping it might be as simple as a relay (seems there is a relay for the self-leveling sensor), but I cant seem to figure out which relay it is when Im looking at it - took a pic and can post if you'd like/need. But, and maybe it's the angle Im viewing at, it just doesnt seem to match up with what I find online as far as relay location.

But, obviously, would like to try to the 'cheap' things first before swapping out expensive parts on her car while chasing down this issue.
Other repairs have been made before (earlier this year) by a Euro shop in WS, trying to avoid that due to A) their cost and B) their attitude towards their customers

 

[wvsig]

I have owned A D2 and a D3 Audi A8L. Both of these cars has air suspensions. The first question I would ask is do you have a Vag-com and have you pulled the codes. If you do not have a Vac-com and are going to keep the car for any amount of time I recommend one. https://store.ross-tech.com/shop/vchv2_ent/ I used to own the 3 Vin unit and used it for my D3 and the wifes VW GTI. Sold it when I sold the A8L for $100 so over its life it cost me $100. My last A8L was a 2008.

The Audi air suspensions have 3 places where they usually fail.

#1 is the relay which is located in the dash on the drivers side in an A8 up under the steering column.
#2 is the compressor which is located in the engine compartment near the firewall also on the drivers side.
#3 is the air bags themselves.

What happens most of the time is that the relay fails. The compressor is then stuck in the on position. The compressor is made to run hard for a short duration and then shut off. Since the relay failure causes the compressor to stay on longer than designed with no other fail safe it burns out the compressor. This often happens overnight or after a long day at the office. You end up replacing the relay and the compressor because of a $15 relay failure.

The other thing that happens is that the air bags themselves inside the suspension system fail and you get a leak. Most of the time this results in one side being lower than the other. Depending on the system IIRC the other side will adjust to match the lowest or highest point so if the drivers side bag fails the passengers side drops as well to allow the car to be driven.

Since the compressor starts and stops my guess would be is that you have a bad air bag inside one of the fronts. IIRC the front and back run on the same relay. Sometimes there can be air leaks in the hosing but it is much less common than what I described above. Some people have rebuilt the air bags inside the suspension but most people replace them with remanufactured parts. I can't remember right off the top of my head which is the best company for the rebuilds but that info is out there.

I think this should be the location of your relay.

 

[HMP]

I have owned A D2 and a D3 Audi A8L. Both of these cars has air suspensions. The first question I would ask is do you have a Vag-com and have you pulled the codes. If you do not have a Vac-com and are going to keep the car for any amount of time I recommend one. https://store.ross-tech.com/shop/vchv2_ent/ I used to own the 3 Vin unit and used it for my D3 and the wifes VW GTI. Sold it when I sold the A8L for $100 so over its life it cost me $100. My last A8L was a 2008.

The Audi air suspensions have 3 places where they usually fail.

#1 is the relay which is located in the dash on the drivers side in an A8 up under the steering column.
#2 is the compressor which is located in the engine compartment near the firewall also on the drivers side.
#3 is the air bags themselves.

What happens most of the time is that the relay fails. The compressor is then stuck in the on position. The compressor is made to run hard for a short duration and then shut off. Since the relay failure causes the compressor to stay on longer than designed with no other fail safe it burns out the compressor. This often happens overnight or after a long day at the office. You end up replacing the relay and the compressor because of a $15 relay failure.

The other thing that happens is that the air bags themselves inside the suspension system fail and you get a leak. Most of the time this results in one side being lower than the other. Depending on the system IIRC the other side will adjust to match the lowest or highest point so if the drivers side bag fails the passengers side drops as well to allow the car to be driven.

Since the compressor starts and stops my guess would be is that you have a bad air bag inside one of the fronts. IIRC the front and back run on the same relay. Sometimes there can be air leaks in the hosing but it is much less common than what I described above. Some people have rebuilt the air bags inside the suspension but most people replace them with remanufactured parts. I can't remember right off the top of my head which is the best company for the rebuilds but that info is out there.

I think this should be the location of your relay.

No vag-com

I'll watch the video in a bit and get back to you on updates

Yeah, the compressor is coming on, the back two are raising, but neither of the fronts are coming up which is why I was HOPING that maybe it was the leveling relay...but I just couldnt figure out which relay it could be. Going to get a new relay tomorrow for her and update.
IF you think of the company that does the bags, please let me know sir.

 

[wvsig]

No vag-com

I'll watch the video in a bit and get back to you on updates

Yeah, the compressor is coming on, the back two are raising, but neither of the fronts are coming up which is why I was HOPING that maybe it was the leveling relay...but I just couldnt figure out which relay it could be. Going to get a new relay tomorrow for her and update.
IF you think of the company that does the bags, please let me know sir.

Good write up on the Air suspension.

http://www.volkspage.net/technik/ssp/ssp/SSP_292.pdf

WABCO makes the compressor.

Arnott for the struts. https://www.arnottindustries.com/products/audi-air-suspension

 

[wvsig]

Oh one last thing if you are replacing the compressor or the struts you will need a Vagcom or other Audi tool to reset the height of the system to stock.