Link is to a pix of the Schrader valve on the front of the compressor manifold on my 200q20v sedan. It's the low pressure access: http://www.pbase.com/kneale_brownson/image/99723804
Fred Munro <munrof at sympatico.ca> wrote: I believe the low pressure switch port contains a Schrader valve, so you just unscrew the switch and screw on the adapter. You don't have to empty the system.
I've attached the post from Tom Green, the chap who found the adapter.
Fred
I have broken the code on a/c charging through the low pressure
switch port. This has been a sore
point with lots of listers for a long time. So I decided that I
must "carry a message to Garcia".
http://en.wikipedia.org/wiki/A_Message_to_Garcia
I didn't have the problems Major Rowan encountered in carrying the
President's message to General
Garcia. It was as simple as reading Paul Waterloo's A8 posts on the
correct way and poor man's way to
recharge the a/c system. Please read both the posts, as they contain
essential information for recharging
the a/c system both by the correct factory method and the shortcut.
I am not here to encourage you to
recharge your system by either method. Unless you are confident in
your ability and knowledge, take it
to a professional. Otherwise, use at your own risk.
http://forums.audiworld.com/a8/msgs/99732.phtml
http://forums.audiworld.com/a8/msgs/135287.phtml
There are follow on posts that show where Paul Waterloo sourced his
fitting.
I got mine at Midway Auto Supply. It is a FJC Air Conditioning
Products R134a Tank Adapter --Part# 6016.
I don't think a group buy can save over $2 unless there are a lot
more interested than I know of.
http://www.midwayautosupply.com/p-7636-fjc-air-conditioning-products-
r134a-tank-adapter-6016.aspx
And, yes it works. It is a quick disconnect fitting, so if you are
using old screw-on fittings for your refrigerant
can or manifold, you will have to get adapters or a new hose set. I
encourage all to use a gage set, but otherwise
you are on your own.
Tom
-----Original Message-----
From: mboucher70 at hotmail.com [mailto:mboucher70 at hotmail.com]
Sent: July 5, 2008 7:27 PM
To: Kneale Brownson; Fred Munro; quattro at audifans.com
Subject: Adding Refrigerant without a Low Pressure fitting
Kneale, I've got a good sense that mine doesn't have a low pressure fitting. Just to be certain, can you help me locate where it would be on yours? The "front of the return manifold on the compressor"...if I recall the compressor is below the radiator, out of sight. Would I be able to see the black capped low pressure fitting on your 200q20vs from the same vantage point that I could see the white capped high pressure fitting? Or would I need to be under the car to see it?
Fred, in order to add the low pressure adapter to a car that doesn't have one, I'm assuming that you'd need to first empty the system of existing coolant?
I'm wondering if its possible to add refrigerant via the high pressure fitting, with the car turned off. I figured that the aerosol can is probably pressurized enough to overcome the 60psi and get at least some refrigerant in, but it surely won't overcome the 150psi present when the a/c is on. I appreciate that I'll get a lot smaller fraction of the can into the car via the high pressure valve at 60psi than via the low pressure at 30-50. The only impact of this is that I'll require more cans. Anyone see a flaw with this?
----- Original Message -----
From: Kneale Brownson
To: Fred Munro ; mboucher70 at hotmail.com ; quattro at audifans.com
Sent: Saturday, July 05, 2008 5:38 PM
Subject: RE: How to Determine if your Audi is Actually Short of Refrigerant
On my 200q20vs, there's a low pressure fitting on the front of the return manifold on the compressor. Black cap. That's where I've put in refrigerant.
Fred Munro <munrof at sympatico.ca> wrote:
You've connected to the high side adapter, as indicated by the lower
pressure when the compressor cycles off.