I have a 1984 VW Vanagon. Awhile back the brakes went out, they lost pressure and the pedal went to the floor, if I pumped the pedal it would regain pressure but lose it again after a few presses. I got a new brake master cylinder and after I installed it I couldn't get the front brakes to bleed, I thought it might be a bad cylinder so I had it replaced and the front brakes STILL won't bleed.

Any ideas as to what it could be? Could something else be broken or maybe I'm bleeding them wrong? Thanks.