Allroad Air Suspension Compressor strip & repair

Hi Andy,

Thanks for getting back so quick. I'll get out tomorrow with a tape and see what's happening.

That's sounds a possibility that the reserve tank is pressurising while I'm driving so when stopped a change in level appears silent as the pump may not actually be running and the bags are just filling from the stored pressure in the tank.

Are you saying that the system is programmed to drop to level 1 while parked? If so that would explain the various hisses (definite valve controlled hisses not leaks) and why it allways wants to lift it's self when first started (but always errors).

I'll measure tomorrow as well as purchase one of your kits as the pump is clearly not happy regardless of any other issues.

Thanks again

Charlie

Hi Andy,

Just to let you know that I had the repair kit fitted today, but unfortunately it hasn't resolved my problem. There was a fair amount of white corrosion around the ring seal, which after some scrubbing looked really good. I'm pleased I did this anyway as I'm sure it's revived the compressor to its original working order, and one of the parts that could have been at fault.

One question though - when the compressor stops working i.e. at the end of its cycle, is it supposed to blow air around the unit itself? After the repair kit was fitted, I had my hand jammed near the compressor (on my car found between the offside front tyre and the fog light), when it stopped vibrating I felt a slight whoosh of air around my hand.

Adrian

Hi Adrian,

yes it vents air each time it stops to help remove pressure in the compressor & output line and some say to help remove moisture from the compressor and airline, the kit will have renewd the output pressure hence this Whosh is now more noticeable once the compressor stops, it should not do this when the compressor runs only the second it stiops it will release air for 1-2 seconds, is this what you get?,

If so for now with your problem we need to focus on this fault code you have mentioned to see what it is, and why it is stopping the system, confirm what fault codes you have now, read and clear them, then re read them once the light comes back on,

on your model can you request the car to lift to a different height? if so does it change heights? (I think it may just be a self leveling option for the rear of your car rather than an option for the driver to change heights.)

im trying to work out if their are any symptoms rather than the light just coming on or does it all seem to function ok, other than the error light comes on.

regards

Andy

Hi Andy,

I have a thread open with my cars problem over in the A6 C6 section of these forums.

The air that I felt around the air compressor lasted for 1 - 2 seconds immediately after the air compressor stopped compressing so I'm happy about that because it's done exactly as you've described. I thought maybe the air compressor didn't go back together properly causing an air leak or something!!

After the refurb kit went in yesterday, immediately after the car was lowered off the ramps, the system didn't work. I had it set to 'Comfort', and tried to put it to 'Lift', but the car didn't raise at all, and the orange light came on and the MMI greyed out - same as before. After stopping the engine and restarting it again, the MMI screen goes back to normal awaiting an input for a different ride height with no lights on the das - again, same as before. I drove it home (about 50 meters) and sulked for the rest of the evening.

However, today was different. When starting the car this morning, no lights at all and MMI was fine, awaiting an input which happens as usual. On my way to the next village along, the green light came on and stayed on for about 5 seconds. Still in 'Comfort' mode, I drove for about an hour and a half in total (3 half hour long journeys) and no light came on at all. When I got home I felt confident enough to put the car into 'Lift' mode, which it did eventually. It took about 30 seconds or so for the rear end of the car to start lifting, and then the front end lifted up. No lights on the dashboard at all. Maybe the car needed time to fill up the air storage tank?

I will get the car scanned for errors and reset them as I'm sure there will be some from yesterday. I will report back once I've had this done, but I doubt it'll be before the weekend now.

Yes on my car you can select the different heights, it's NOT just the self levelling rear end. It's basically an A6 C6 Avant with the Allroad suspension as one of the options.

EDIT: OK, so I took the car out to the petrol station about 5 minute drive away, and the suspension didn't do anything. The MMI greyed out and the orange light came on. I had the car on 'Comfort' mode and tried putting it to 'lift'. I will try when I next drive the car on a longer journey to adjust the suspension so it's warmed up.

Quote:

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Originally Posted by bagpipingandy

Hi Charlie


it does sound like a tired compressor symptoms especially when cold, but you say it doesn't lift when cold? I guess you mean its slow it actualy moves but just slow and if it tries for 120 seconds and does not reach the requested level it will put the error light on solid, but then ignition off and on it will try again?
so my questions is when cold does it move? (try a tape measure on the rear wheel arch to the ground) or does it not move at all? if no movement when cold, maybe a stuck valve if it does not lift at all when cold,

if it does move and can get to the next level with a few ignition offs and on agains,: its only a theory and not a calculated answer I have I'm afraid but, It may lift faster when "warm" as the car will have topped up the storage tank when driving a while giving potentially more air to help lift it, but when parked the system will use the air up to do any levelling when you get out the car and so could be a reason when cold next morning the system is low on air and struggles to lift and get into shape,

also
does the car sit at level 1 when parked overnight or does it sink to the bump stops?

regards

Andy

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Hi Andy,

Just been out and measured the ride hight change. Sure enough there was movement, it was slow and timed out but there was movement.

Will now proceed to Ebay for one of your kits... Thanks again for your help.

Charlie.

http://www.ebay.co.uk/itm/161372854977?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Hi there.

I had an air leak in the valve bock so that got replaced. However, the suspension still doesn't rise as it should. When cold it's fine, but after a while the compressor shuts down when hot. The Audi specialist where the car is at currently has said this. I fitted your refurb kit a couple of weeks ago which has made a difference, but it's still not 100%.
I found this on ebay - (see above link, not sure why it got inserted there). Would these parts help bring the compressor back to life? Do you do one of these kits? Is there anything else to do on this compressor? Or would I be better off getting a new compressor? Do you have any?

Kind regards,

Adrian

Hi Adrian,

the ebay link you show is for the drier unit decissant and will not improve the compressors air pressure output performance, its purpose is to remove moisture from the system, but afraid it will not make any more air from the compressor, but we can check a few other things which maybe wrong in the compressor.

does your car sink?

or just slow to lift?

there are other things to check inside the compressor if you can disassemble it, the one way valve at the top of the cylinder is worth checking, what condition was the cylinder in? was it scored?

I don't offer new compressors but I will have some refurbished compressors ready in 2-3 weeks

let me know 1st your suspension symptoms

best regards

Andy

Andy,

Is it still possible this drier unit can block because of its age and possible moisture effect on contents inside it and reduce amount of air that passes to compressor and thus reduce its performance in that perspective?

Hi All-rod

In my opinion it cannot really block up enough to stop 220PSI from the piston, but (again only my opinion) their are many other components which require to be working to get the full performance, 1st main ones being there are 5 valves in this compressor each must be sealed closed to generate this kind of pressure, these are far more likely to be preventing the full pressure build due to dirt, or brocken springs,

the compressor also always vents air to remove moisture everytime it stops running, this is the PFFFSSTT you hear for 1-2 seconds exactly when the compressor stops, it does this to remove pressure from the airline line and any moisture in it, I have opened a lot of compressors and most certainly are moist in the drier unit but not so much they are blocked, any soaked compressors have usually injested water in through the air intake at some point which rusts and jams the N111 and pressure relief valve.

if the cylinder is in good condition the compressor should be repairable back to 220PSI, the valves can be removed cleaned and checked fairly easily, the only other compression issues can be a cracked drier body, or air intake vane bent open or even blocked air intake filter.

regards

Andy

Ok, thanks for this explanation. Mine still runs fine since I replaced the ring, most of time cant even hear it run and only for short periods, even though sometimes it does lift pretty slow it does the job and cant really complain!
As you say the are many other factors involved that may be causing slow lift now most of these cars are over 10 years old...

Cheers,