Finally Sorted the problem, the initial garage I took it to overfilled the system, instead of 950g they put in 1725g
The aircon specialist couldn't believe it, he said the noise I was hearing was the clutch kicking in and out, he said it was a miracle that the compressor was not damaged.
The aircon is now working perfectly, so lesson learned, I will be using an aircon specialist from now on.
Just for information for all you peeps in South Wales the guy that sorted it was Steve Penpraze mobile air conditioning service. 07973 912032 he's brilliant and has all the specialist kit on his van. He said he'd worked on quite a few Bongos and Freda's over the last few years.
