D4 aircon leak

[Saff]

Hi folks,

I'm looking for a knowledgeable sort who can tell me the location of the aircon expansion valve.

The system will hold a vacuum and 10 bar of pressure on test (no engine running), recharge with refrigerant and work but will leak away in use over a few days. This suggests to me that it could be either (or both) the expansion valve or the compressor as they are the only moving parts. I'm kind of hoping it will be the compressor because it's accessible on the 4.2 tdi but the expansion valve may not be.

Any pointers to its location will be appreciated.