Pedal goes to floor

nm9stheham said
If properly working, there should be some pedal pressure before the floor as you are thinking. One of 3 things comes to mind:
1) The MC is now faulty and there is a leak between the front a rear sections
2) The front caliper pistons are pushed back a bit for whatever reason and won't pump up properly now.
3) The MC has all sorts of air in it now. If you left the rear lines open for a long time, and then pushed the pedal then that is the most likely thing going on. The MC may need to be completely 'bench' bled again (which can be done on the car). You will only know if you hook up the rears and try to bleed them; if they don't bleed right, then bleed the MC.

I would never push on the pedal with part of the system open, BTW; that presents the possibility of getting air in the MC and needing the re-bleed the MC. I also plug the open lines, keep fluid in both MC reservoirs, and work fast for the same reason: keep air out of the MC.

The biggest reason I left the lines open was to try and totally drain out the old fluid from the lines because it's like 30some odd years old. The old wheel cylinders were real cruddy inside.

Thanks for the info. I'll check it out and rebleed the master if I have to. I'm not so sure the front calipers aren't frozen as it's has been sitting for so long. There are no rebuild kits available for the front calipers any more for the Dana 60 front axle, so I haven't pulled them apart.