Thanks Gary and rissy, I was reading that post before about testing the servo unit. It s a very good point to check.
I have tested it like you described and it passed thankfully, could not hear any hissing.
I will re do the test again later with my vac pressure test kit just to make sure there are no leaks.
I loaned it to a mate and have to get it back off him.
My biggest issue was slightly spongy pedal feel, but seeing as the hard line supply was virtually rusted out that might explain alot lol.
Again thanks everyone for the comments and suggestions it helps massively
Cheers
Shane