Leaking Air Con

I have recently discovered that there was a small quantity of clean oil dripping from the air con compressor unit, it was too clean for engine oil, not the smell of gearbox or brake fluid, initially I checked the 10mm head bolts around the compressor, but that did not solve the problem.

Knowing that I am doing a cam belt change as well as the other items, I waited a few weeks, I have since reremoved the air con unit, the leak is from the aluminium mating face where the two pipes go into an aluminium piece which is held on with one 10mm head bolt, beware, undoing this bolt will lead to the de-pressuruisation and loss of all of your refrigerant, perhaps not too great for health or environment etc, so be aware!! With the pipes off, this exposes two green O rings, there was slight signs of leakage from one of the two ports. Looking on the net, there are many kits with various grenn O rings in, hoever Halfords do a kit of approx 10 O rings for £3.29, the size I wanted was in the kit, but only one of, so I had to but two kits, but still reasonable considering the air con is no longer leaking, also cleaned aluminium faces prior to re-assembly.