Brakes

How did you bleed the ABS control unit? That needs to be done with a scanner program to operate the valves inside the control unit. You would have to take this to a shop to be bled out properly.

I bled it by the popen that go into it the back I was told to do that be a brake mechanic

Pipes

I don't know...all I know if air had gotten into the ABS control unit, you can bleed the brakes all day long and not get a good pedal.

I also did a diagnostic on it but I picked up nothing

what about the rear brakes ? If they are calipers they have to be set right I don't think they will self adjust . If by chance they are drum and shoe they should be all new , you loose a lot of pedal if they are worn , you wouldn't think a small amount of wear would do that but it does .

Yes beatupchevy, if the rear brake shoes, if there are any on this one, are not adjusted up to the drums so the shoes drag a bit, then you would have a low brake pedal. But it sounds like to me they got air into the ABS control unit.