After what seems like forever, the problem has been solved. replaced hoses to/ from resevoir( no effect) replaced P.S. pump(no effect) flushed system( no effect) still leaked:( Seemed like the resevoir was BURPING!! and got very HOT!! SOOOO went after the brake pressure regulator. It turns out when we replaced the front brakes and bomb, a piece fell out of the orifice where the bomb screws in . It was a tri angular piece with a post on it ,held in by a retainer circ. part of the accumulator valving. since it was under the regulator body, it just fell out!! We spotted the little piece lodged by the steering box. whew!!! SO now have really good power steer/ brakes on my wife's '79 733i joy! one for the archives?? griffith davies, onesix/oneseven on the E24 board.