Air Suspension spare tyre filling not working

[darrinsmith]

Hi everyone.

I recently had some trouble with the compressor on my 2003 turbo with air suspension. I had the local shop replace the compressor with an aftermarket unit and everything is fine and working as is should, except I went to use the spare tyre filling hose the other day (to help out an old lady with a flat tyre) and it didn't work. (of course after I have boasted about how great it was to have a compressor built into your car!).

I connected the hose to the filling point as normal, and the red "spare tyre filling" warning came up on the dash board as normal, but the compressor doesn't kick in, and there is no pressure at the filling point under the seat.

The funny thing is, that you can manually press in the little nipple in the filling point itself and get a momentary "phsst" of air but then nothing. The hose is not damaged or blocked either.

The air suspension is working correctly, and the compressor will kick in as required and the accumulator tank is holding air properly. I also confirmed there are no error codes with Durametric.

I assume there must be a valve located somewhere in the line that is not working (ie not allowing air to pass through), can anyone give me any guidance as to what I should be looking for and where it is located). From the looks of it it is underneath the car rather than the seat itself?

Car is RHD, if that matters.

Thanks again!

DS

[mudman2]

Hey Darrin

OK this may help.

There is a ring magnet in the mouth of the end you screw in under the seat, this activates a reed switch to turn the compressor on. it drops off. The solution for me was to replace the inflator pipe.

Shame you are where you I have a spare one here since I traded the car just after I got the new pipe, the new ride came with one.

The part number you need is 955-358-0710-02

Mike

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170738913361&ssPageName=ADME:L:EOISSU:US:1120

Edited February 20, 2012 by mudman2

[darrinsmith]

Thanks Mike,

The magnet is still in the plastic bit that you screw on, and the car "knows" the hose is connected (Red warning on the dash board).

So the reed switch must be working.

I guess they must have disconnected something when they put the compressor in a bit further down the chain perhaps...

I'll just have to crawl under this weekend and have a look.

Thanks

DS

[bigbuzuki]

Thanks Mike,

The magnet is still in the plastic bit that you screw on, and the car "knows" the hose is connected (Red warning on the dash board).

So the reed switch must be working.

I guess they must have disconnected something when they put the compressor in a bit further down the chain perhaps...

I'll just have to crawl under this weekend and have a look.

Thanks

DS

Any resolution to this defect?

[darrinsmith]

Sorry to reopen this very old thread, but I did some more diagnosis today.

So I can confirm the following;

1) The air suspension is working perfectly at the moment, and I can hear the compressor running from time to time to keep the system pressure as per normal operation.

2) There are no errors being logged with durametric.

3) When I screw the air fill hose in the car recognises that the hose is connected and show the red "filling tire" message on the dash (so I assume the magnet sensor in the hose is fine).

4) The filling system is definitely pressurised, as you'll get a few seconds of air from the hose as the line de-pressurises.

I took off the plastic panel and verified that all the air hoses appear to be in the correct places, I also re-seated all the electrical connections to the air compressor, and checked the 2 fuses in the dashboard were ok.

So now I'm at a bit of dead end, I can only assume either

1) there is some sort of fault in the car that isn't affecting the rest of the system,

2) the compressor I got (an aftermarket one) is somehow not "wired" to activate the compressor on the tyre fill input.

If anyone has any ideas, I'd be happy to hear them, as I'd really like to have this system working, as in the past I've used it a bit to re-inflate tyres after being off road enough to get to a normal compressor.

Thanks

Darrin Smith

[bigbuzuki]

I've attached 2 plumbing schematics for the air suspension system.

The first is for the Touareg, the second for the Cayenne.

I'm assuming the aftermarket compressor you have may be like the one for the Touareg which did not have the tyre filling feature.

If that is the case then you can see the tyre filling plumbing is not available on that compressor, and is also fitted with some extra check valves which could be causing your issue.

The tyre filling connection is shown as number 8 on the Cayenne diagram, and is missing from the Touareg version.

Edited March 16, 2014 by bigbuzuki

[darrinsmith]

Thanks Big Buz,

Hopefully I can get around to dropping the compressor this weekend to check but the line is definitely pressurised, so it must be connected to the compressor.

There is a small brass valve in-line, and I also suspected that, but it's bonded to the hose, so I'll have to cut it to check it...

I assume it's a one-way valve, I wonder if they put it back the wrong way round....as it looks like they might have cut the hose to remove the old compressor, and have put some heat-shrink type stuff over one side of the fitting.

It seems odd from the schematic that the tyre outlet is not controlled by the pressure sensor, rather through the 2 bleed valves, although from memory for tyre filling the compressor runs almost constantly until it gets hot then the car cuts it out till it cools a bit.

It's just really weird that the line is pressurised, the compressor just won't run....

Thanks

DS

[dapopa9]

Any luck getting this fixed?  I'm having the exact same symptoms.  Dash indicator comes on, air comes out the hose for 1-2 seconds, and then nothing.  Air suspension still works fine.   I had a flat tire that I was airing up fine for a couple minutes then it just stopped - I thought maybe it just needed to recharge or something however that was a couple days ago and it still doesn't work today. 

 

Only difference is I still have the original stock compressor in my CTT.

[xxoioxx]

hi guys

 

am having the exact same symptom where i connect the hose to the nozzle and air comes out only for one second. compressor is aftermarket, just changed it.. tried the same hose on another car and it works (so the hose is not the problem).. no idea if the inflator was working before with the stock compressor, but air suspension works flawlessly. 

 

any info is much appreciated. 

 

 

[Nick Exton]

Dis anyone solve the problem? I have just replaced my compressor as well (exactly the same as the original) but just tried to inflate my SUP.... all I get is a pfffttttt. and nothing..

[kahukusweet]

Me too? Stock 2008 turbo. Anyone know why?