2015 (early) Avant Air con. compressor.

[Magnet]

Hello, 

A family member has a lack of air con. on the above 77K A4. It loses pressure, and the problem has been diagnosed as a faulty compressor (leaking?). 

Have done a quick on line search for a new replacement and prices seem to vary from as low as just over £100 to the mid £300s. 

Wondered if anyone has any experience of buying replacement compressors and could share some good contacts, and/or ones to avoid. 

Also, is this problem relatively common, since I would have expected this part to have lasted longer than it has? 

Many thanks and kind regards, 

Gareth.

p.s. Diesel - incase it matters.