I was supposed to be borrowing my mates vacuum kit but he got last minute tickets to the Olympics so bailed on me.
Anyway all done now, with a one way bleed kit from Halfords and the front bumper off so I could jack the back up as far as possible. Four separate air pockets came through and another when I pulled back on the cylinder, I was amazed at how much air was in there.
It took two litres of fluid to get the bugger done, I literally had just enough left to top up the pot when I was finished, I was hoping to change the brake fluid when I was done but that will have to wait now.
Thanks for all your help guys