Just installed a 15/16th piston MC on our 70 Challenger. Awaiting new front disc pads to arrive to replace the very soft and dirty pads currently on car.

They were being used because with any cleaner pads, I had almost no front brake action on this non power brake car converted from front drum to front disc,,,car retains rear drum.

I did bench bleed new MC very well, brakes are much better than before, but must still bleed at each wheel as likely got some air in lines when I broke them from old MC to attach to new MC,,,brakes are full pedal, very slightly spongy but still ok.

Question. While awaiting arrival of new pads, if I were to bleed only rear brakes today, are the front brakes completely and totally isolated from the rears so that if I should drive the car that I can assume that I would not be required to bleed the rears again when I bleed the fronts later.

I plan to bleed the fronts once I pull the wheels and replace the pads.

Don't believe that I had ever considered this issue before,,,,likely others have.