aaaggghh! Swaped the 8.5"GN rear out of my 78 Elky and bolted up the 9" we had been saving for my Malibu. All the brake hardware on the rear is NEW, including the wheel cylinders. I had to bend some new lines and make a support bracket for the rear distribution block/brake hose. I figured I'd have to bleed the brakes, but nothing works. No visible leaks and the resevoir stays full (unless I'm bleeding them) The peddle is nice and firm until I start the car, then the peddle is mush. I've bled the brakes like normal 3-4 times (two poeple), gravity bled them, used speed bleeders, and tonight used a vacuum pump . Nada, Zip, Zero, Zilch...same thing, nice firm peddle until I fire it up. Then...mush. The brakes worked fine until the rear swap. Proportioning valve? Could I have mucked up a fitting/line where air gets in but does not leak fluid? Don't want to start replacing parts if it's just something simple I'm missing.
