Confused man

Ok, I bought this 1998 A4 Avant Quatro a while back and since I have been working on the AC, rust proofing it and so on. I have since changed the Condenser, Compressor, AC Lines, Accumlator and a whole bunch of Orings. Not too happy with all the Aluminum Nuts welding together on this car, which caused me to change more parts than I should have.

Now, After 2 Months, I went to charge the System, with 2 PAG46 Oil and then use R134A Cans. I was doing good until I noticed the Gauge would not stay @ 40Psi, which was an indication of a leak. So, I went inside the Car and noticed a faint hissing sound,,,, all of the sudden, white Gaseous smoke came out of the Vents. I suppose this was the PAG46. So, obvisoulsy I have a leak in the worst place. The Question I have is,,,, How do I access the Exchanger. I looked under the Dash and I have no idea how to take the buttom section off. Doesn anyone have any idea where to start or how to start? Has anyone any ideads of where this Leak most likely be behind the dash,, I wonder if it is a common problem.... Any help would be appriciated. Thanks

jimrobertson

Kris Hanson has a write up with pistures on this somewhere on the web. BIG JOB!

Confused man

Oh God, I was affraid of that. The AC Core is a Bitch to get to... Why did Audi Engineers make it so difficult to get to tbis one.

I saw one version of Kris's instruction. I wonder if there is a better version out there with better pictures.

AudiMick

You need the factory Bentley manual, about 10 hours work. If you sit in the diver seat everything you can see needs to be removed.

Change the heater core at the same time otherwise you will be in there again.

I had to replace the core on my 1996, it's not pretty.

Confused man

Yes, I have removed everything. I got to the core. I think the problem occured when ICE formed up in the Core Housing. Right were the Input Cabin Filter is mounted by the Windshiled, directed all the rain water in this area. Even though there is a drain, I think ICE did the trick. I have some nice Picture that I will post later of the entire thing.

Confused man

I put everything back together now. I have a theory on how the AC Core Failed. The Cabin Filter on the top was wet, which was caused by misplacement of the Rain water catcher. The rain water accumulated in the buttom of the AC Core/Heater Core box and froze, which then cracked the AC Core..

Confused man

One thing I would recommend is to obtain the Radio Removal tool, which I think you can use the same tool to get the AC Control Module out too. The hardest part of this whole process was to get the 2 Screws out that hold the upper Vent. My fingers cramped a couple of times trying to get the screw out. 8mm screw from hell.

Every screw or bolt you take out, you need to put it back in its original location so they don't get lost. And take tons of Pictures of every stage from different angles.

Confused man

Here is a picture of 1999 A4 1.8T Avanat. The new Heater Core came with a weak foam. I had to go Advance Auto and get a better Foam.

a4_1.8t_01

That may be why it exploded the way it did. All the air needs to be removed from the system.

Confused man

I am still not happy with the way Compressor is working. I was under the impression the Clutch needs to kick in and Out of the Compressor. I want to put a LED indicator on the Compressor Source to see visualy when it comes on and off... Unless Audi Compressors are always on.