Allroad Air Suspension Compressor strip & repair

**Tel2** · 23-05-2016,01:12 PM

Hi bagpipingandy. You seem to have come across many of the problems with the Allroad suspension but I couldn't find one which matches mine. I am hoping you may have come across it.

Vehicle: Audi A6 Allroad 2.5 Tdi 2005 C5

The problem is intermittent which makes it very difficult to pin down. It appears to be related to the suspension lowering valve for the front nearside suspension. The problem started with that suspension arm lowering itself overnight. It would pump up to normal height when started in the morning but would still lower itself overnight. After much testing it was discovered that if the suspension level was set to level 2 (the lowest level being 1 and jacking level 4) then the suspension did not lower itself overnight. There have been no problems with the suspension while driving until last week when the front nearside suspension started lowering itself during driving. For around 400 miles it would not pump up because the pump was cutting out after trying to raise it to driving level. Overnight this cleared itself, the suspension pumped up to level 2 and stayed there. As long as the level is set at level 2 the suspension has only lowered itself once overnight. If the level is set to level 1 it lowers itself constantly, even when driving.

There are no error codes when the problem is not present. When it is, the only code which comes up is the one regarding control height, there is no indication as to the problem. If you reset the code and watch while the pump is trying to raise the suspension the reservoir pressure varies between approx 5 and 6.5 bar but the reading seems to show that the reservoir valve is off and so is the pump, even though you can hear it.

My only thoughts so far are that the valve is sticky or the pump is not reaching a high enough pressure to open it. The pump has one of the repair kits already fitted as that was the first attempt to fix the problem.

Any ideas? All help would be much appreciated. Thanks.

**bagpipingandy** · 24-05-2016,01:06 PM

100% airbag leak

They only leak at level 1, sometimes 2, but not at higher levels due to how the perished rubber sits

This would throw the 01400 code and sometimes overheat error

Best to replace it soon or it will burn out compressor.

I have new front airbags in stock message me for more info.

Best regards

Andy

**Tel2** · 24-05-2016,01:20 PM

Thanks for the reply Andy. All airbags have been checked several times for leaks, none can be found. Are they missing something?

**bagpipingandy** · 24-05-2016,02:07 PM

Yes, you can only check for leaks with the car on the ground at level 1, if you jack it up it will not leak.

Put car on level 1, turn steering full lock, get bucket if soapy water and put it all over lower bend if rubber, it will bubble.

Let us know what you find.

Best regards

Andy

**Tel2** · 24-05-2016,02:36 PM

Thanks again Andy. My guess is that they put it up on a ramp to check for leaks and I don't know what level they were testing at. The vehicle is in at an auto trans specialist today but I will try the soapy water as soon as I get it back and let you know.

Regards, Terry

**All-rod** · 13-05-2017,08:53 PM

Hi chaps, after numerous years of trouble free air suspension now the compressor stopped running and i have removed it to find that the is no life from it when voltage applied.
Do you Andy or anyone reading this have any pictures of motor disassembled or pointers what to expect there? i am interested to see where the wires go inside the housing, i am planning to strip it apart tomorrow...
I could be wrong but i also could not see any voltage coming to motor when ignition is on?
Cheers.

**bagpipingandy** · 14-05-2017,02:34 PM

Hi, if you put 12v direct onto the compressor motor plug the compressor should run, if it does nothing the motor is gone, the 2 long bolts hold the end cap on the 2 wires just go to the motor brushes, its either the brushes worn or the magnets came off the outer casing.

How are you checking for 12v on the car?
If checking for 12v from the car you will not get any voltage if the compressor is removed as it will throw the error light on solid if you unplug the N111 valve.

Regards

Andy

**All-rod** · 14-05-2017,04:11 PM

Andy, I took it apart and everything appears to be fine there, have continuity up to the brushes. I assume 13v from AC/DC adaptor should be sufficient. Motor spins free, ring still ok. Weird.

**bagpipingandy** · 14-05-2017,04:53 PM

Hi, it needs a large current, use the car battery to test it

**All-rod** · 14-05-2017,05:10 PM

Ok Andy thanks. Further time looking at it spent and i have decided to take a closer look at armature and found that the problem is with two of copper wires where they are crimped at the top - they have snapped off... I have added pictures with screwdriver pointing at one. Do you think this is repairable somehow?

WP_20170514_16_06_46_Rich.jpg WP_20170514_16_43_41_Rich.jpg

Update: I have managed to solder the two wires retested and fitted back to car. It now works again as before. Time will tell how long the repair will last.