I would put this in the tech section, but this is for my new truck-I guess it's probably the same, though. All the brake lines as well as the master cylinder have been replaced. It was driven for quite a while without rear brakes-only the front. Now the rear brakes won't bleed

-the fronts work fine.

Does the proportioning valve need replaced or should it be reset. It says in my Haynes book for my satellite to turn the key to on and push the brake pedal down slowly to reset the proportioning valve. It's at my Dad's right now, so he was going to try it and see what happens. I was hoping somebody on here would know something about it. Thanks
Landon