Also, thank you for the fast welcome =) I realize this is a jag forum, but I was wondering if anyone had a good place to look up the function of the valve control block, fixed the compressor, but the block seems bad now, it shows no codes. A friend at the Audi shop near me said the valve block was his best guess, but he stopped short of smuggling me out any diagrams lol, iv been pouring through google links for hours lol, I only found 1 good one, and its in Russian lol!

 

"As for the guy that suggested shimming, just thought id let you know, I rebuilt mine about 5 months ago, just wrapped 2 layers of duck tape around the groove that the piston ring sits in, snapped it back on, work like a charm, not 1 problem since lol."

Easier than I thought-we have got Jaguar and Wabco beaten!

 

Hi kalboon, head over to vwaudiforum there is lots of allroad stuff there, you can check the measuring blocks in group 34 to check the valve block operation using vcds, I am away just now and have limited internet. But put a new post the the VWAF c5 section and I will reply soon, also I have lots of wiring diags for you to play with, what's the suspension issue?
regards

Andy (allroad owner)

 

Hi Andy, I'm on vwaudiforum now, just thought I'd give you a heads up, my issue is this, one day car will air up just fine, next day only the back will air up, then I'll shut off the car to recycle the compressor, and the back deflates lol, i know the system is charging the air tank on board, because I took the line off of the reservoir to check, and it had a full tank of air, car shows no codes, I have a friend that works at the vw/Audi shop near me, he plugged it in, no codes at all, but he said it seemed like a bad valve body. Also, when I duck tape wrapped my piston, I wasn't aware of the rebuild kit you sell, me thinks I'll be ordering one, fix it the right way lol.

 

I finally got around to removing my air compressor while I rotated my tires this weekend. The install went perfectly, with well defined instructions included ... and pictures (thanks for those!). The most difficult part of this project was getting the compressor away from the car...the fog light housing took some deflection before the compressor could slide out from those vertical 'vibration dampening' guiderails.

Two electrical plugs, one incoming air line, one outgoing air line, one bracket, and the nuts on those guide rails...and out it came.

Great bit of kit, the winners of the prize drawings will be surprised of the quality and ease of installation.

 

Good work, I'm loving the feedback, glad you like it

best regards

Andy

 

Just thought I would let you all know I used Andy's kit/new piston ring several moths ago and have not yet seen the "air suspension fault" message since installing it. If you have any DIY ability you can do this in about 1.5-2 hours no problem, I suggest removing the fog light assembly for visual and room to work reasons. Thanks to Andy for this solution.

 

no problem, thank you for reporting back, your feedback is crutial to share our experiences, it all helps to save some cash fixing our cars to prevent them eating our wallets!!

best regards

Andy

 

Shimming the air compressor seal is indeed an excellent idea. I bought a repair kit (= mainly the seal) at "bagpipingandy" in the UK for abt. 50 € but this replacement itself did not solve the low-pressure-problem.
For the shimming I used a 12 mm-wide ,0,075 mm thick teflon tape that they use for pipework tightening.This material has several advantages:
-it's easy to applicate on the groove in the compressor piston
-the dimension-increase per winding is very small
-the teflon tape itself has a high wear and temperature resistance (up to 260 °C)
I put 5 tape-layers on the groove with an overall diameter-increase of less than 1 mm which gave a tight fit of the piston-seal in his cylinder.
The result was a raise of the compressor pressure to more than 10 bar and all "air suspension anomalies" solved plus a benefit of more than 600 €.

 

Personally I'd use metal; I'd be worried that the tape would work loose and get out into the cylinder and generally block things up.

What's the thickness of the aluminium in a Coke can (just a hint of Zen & the Art of MotorCycle Maintenance ?)

Did you shim the old seal, or the new one ?

 

Excellent idea using PTFE Mr De Ploey!

I am surprised that the replacement seal did not solve the problem and Andy's comment on this will be interesting.

When you think about it cylinders will have various diameters due to wear and his seals must be "one size fits all",most of the wear will be on the used seal of course.

One forum member has used duct tape successfully for months and therefore I think that PTFE would last, remember that the seal will be tight against the PTFE underneath it.

 

Hi all, Interesting you found it did not work well, I'm afraid my 1st thinking would be you need to make sure when fitting the new ring it is around the correct way as if upside down it will generate very little pressure as it will be caught over the small pin in the piston head itself, the piston ring must fit free around this small pin. if you have the new ring look at the inside to see if there are markings where the pin has been pressing into it.
The cylinders on these compressors are tapered and so although putting shim behind the ring will open the ring, the ring has to open and close as it moves up and down in the tapered cylinder,
The new ring should produce 16BAR, did you shim the new ring or the old ring? I would think the new ring may be too tight with shim and it would be noisy or heat up very quickly? do you find this?
I find the cylinders do not actually wear as the head is cast with a thin 0.002" (0.050mm) PTFE coating, the PTFE ring is very soft and takes all/most of the abuse, so at-worst if the cylinder were to wear there would be no PTFE coating left in the cylinder and it would be useless, I have seen scratched cylinders but non with the coating worn off.

Let us know if you can re try the new ring but I understand if it is too much trouble with getting it all out again, I can offer a refund if you return the ring to me should you prefer.

let us know what you think

best regards

Andy

Over 1000 rings sold now, many copy cats copying my idea now .
make sure if looking for a kit you come to the original compressor kit by bagpipingandy!

PS: a metel can thickness is 0.003" (0.075mm) thickwhich would add 0.006" (0.150mm) in diameter to your ring if used for shim

 

Ah ... right ... but I didn't appreciate that the cylinder bore is tapered; shimming not as great an idea then.

 

don't get me wrong the shimming will help a tired compressor, but as it is tapered it only forces the ring against the cylinder rather than using the rings natural "springiness", I tried options of shimming also before I tried machining a new ring which felt x10 better, hence the compressor kit was born,

I would interested to find out why the new ring fitted by De Ploey above didn't seem to work, to see if we can resolve this, Herman can you give us more info as to your thoughts?

best regards

Andy

 

-----------------------------------------------------------------------
Dear all,

By just replacing the old seal with the new-one the pressure didn't exceed 4 bars which continued to give fault-messages and system failures.
I shimmed the new seal with abt 5 layers of teflon tape ( a diameter increase of ca. 0.75 mm ?) which still assured a certain "springiness" on the seal.
I only stated that the pressure raised to more than 10 bars and that running the compresor, by shorting it, for more than 3 minutes gave no extra heat or overload symptoms. Since then (2 months ago) the air suspension system works flawless.
PS personally I think that it is wise to renew the seal anyway after so many running hours (mine was after 98.000 km)

 

Hi De Ploey, thanks for the info, out of interest how are you measuring the pressure, is it with a Guage screwed in to the 1/8 BSP fitting, or hand held on the compressor output?, way back when I 1st started I used to hand hold the guage but then I realised it didn't give steady readings compared to screwed in to the 1/8BSP fitting, my reason for asking is the new rings should push 14-16Bar and this value is only really limited by the pressure release valve on the compressor, for which there is 2 settings on each compressor to limit the output to 14 or 16 Bar.

I would hope it is not the new ring purely as they are made to tight tolerances and I check them in batches on a test rig for performance, however its not impossible for it to be faulty, I would be happy to replace it with a new one if you prefer, the other issues could be a one way valve deteriorated, although I would think shimming wouldn't improve it that much?

If it is easy to check I would recommend to re-check if the ring is fitted around the correct way as this is something which will definitely reduce the output, or if possible provide photos which may assist me with what could be wrong with your poor performance findings. Of course in understand if you just wish to leave it well alone as sometimes if it isn't broken don't try to fix it, springs into mind!!

if you have any questions please just ask & I will try to help

regards

Andy

 

I think that this maybe an older pdf supplied by Andy (OK for Audi) but the photos clearly show the alignment of the new seal.

HTH.

Piston Seal Alignment.

If I am incorrect, let me know, and I'll delete.

 

Hi Andy

As a matter of interest,you said that the cylinder bore is tapered,how much of

a taper is there? ie what is the difference between top and bottom diameters between the swept volume?

You also said that the cylinder does not wear-does this mean that there is no ovality?

About 2.5 years ago I had the air susp. light up all day.

I removed the seal and all I could do was stretch the seal a bit (very gently)

and replace it.No symptoms since!

BTW there was no locating pin for the seal-mine is a very early car.

 

I put I'n Andy's new seal about 3 weeks ago. not a single fault light at all now. it's great!!
mine would go on everyone 3 or 4 days. such am investment. keep up the good work Andy

 

Yes the photo on page 2 shows the pin and piston ring in close detail: Piston Seal Alignment.

sometimes the pin does not stick out much and if the piston seal is upside down it will ride over the pin but it will still all fit back together but it prevents the ring performing well, if upside down it only puts out 3-4Bar if lucky,

regards

Andy