Brakes wont release

Well I had no issues with my brakes (that I knew of) with my drums. I never really drove it though, but now I swapped the front to discs. The issue I'm having is the rotors require more effort to turn than they should, I really have to try. Now I was able to make them right spacing the master cylinder out, I took the spacing out and it was still fine. But now its back. Could this be my master cylinder out of adjustment? How exactly can I adjust it? Or could it be my proportioning valve not releasing pressure?

Also, when I bled the brakes, it didn't suck any fluid from the rear resivour. Bleeding front and back I had to top off the front and the back only went down very little. This is on my 67 f100 2wd.

My guess is your master cylinder has a 10lb residual valve in it for t old front drums that's holding pressure on the new calipers. 2 lb is all that's required for disks.

I had the same issue on my truck, baffeled me till I realized it only did it for awhile after I pumped up the brakes. If it sat over night they turned just fine. Id find a mastercylinder off a disk/drum truck instead of your current drum/drum setup. You can remove the front residual valve in the master but just replacing the master is easier imo.

I'll see what the parts store can do. The master cylinder is new, they might have a disc brake setup. I still don't understand why it only used fluid from the front reservoir I'll jack it up this weekend as well and see if they have freed up from sitting

Something I wanted to know about... If I pump the brakes then let off, then I go crack the bleeder screw, nothing should come out right? I remember checking this and some fluid came out but it wasn't really pressurized. I can check again and give you the results, it may even be something mechanical maybe my slide pins aren't straight enough, and I will try re greasing them. Last time I used silicone paste which it looks like it liquified and dripped off everything.

Justin when I did the swap on my 69 I bought a master cylinder for a 74 f100 with manual disc brakes also make sure the rubber lines are not bad they will make the brakes hold too.The insides will claspe and will not let the fluid return but 1st start with a new master cylinder the drum brake master cylinder don't work real good with disc.

I ordered up a new master cylinder, I also read more into it. How the current one is giving it 10psi, the disk one gives 2psi. And the current one has a valve for the drums that holds pressure. I'll keep everyone updated

So I blead the brakes with the disk master cylinder today, everything works just peachy And the pedal is a whole lot stiffer than before also requiring less travel to get tight FINALLY!!!