No it's not pressure fed its a peddle pumper design. It does work a treat I've been using it to bleed brakes on cars for 3 years. This is the first time I have had a problem and the first time I have done rear brake calipers on a MKII Golf. It maybe that this method is not good enough for this model of car.
My neighbour has a pressur ebleeder so I guess I may have to borrow that and give it a go, but that'll be at the weekend so looks like I'll have to cancel my retest and pay full wack for another MOT which will have to wait till next month now as I've run out of money anyway.
Nick