new MC, but bad brakes

[kevs250]

Hey guys,
Ok heres the deal....about two months ago I had to replace my brakes(1970 F-250 front discs) because I had metal to metal action going on.
I changed my pads and found i had some serious groves in my rotor, and I couldnt turn my rotor because the groves were to big, and i couldnt buy new rotors because i didn't have enough money.
finally i got some new brake pads and installed them and after i bled the system and got the brakes on, i took it for a drive and the brakes were extremely spoungy. I bled them again, but still not improvment, so i replaced my master cylynder because that was what i thought the problem was.
FINALLY after i installed the MC, i bled the system and took it for a drive, and still no improvment
so I want to know if anywere between these steps i could have done somthing wrong.
is it the rotors?
did I install the brakes wrong?
if you guys could help me out, that would be awsome

[QC]

If it's spongy you still have air in the system, you need to bleed it some more.

[kevs250]

I forgot to add, when my brakes are warmed up they hardly work even when i do pump them.
so could that be air in the system?

[ToughOldFord]

Did you bench bleed the MC before installing it? If not you probably sill have air in your system, you can pull your lines the the MC and bleed it right there on the firewall and then hook up your lines and bleed your system again.
Failing that and you're 200% sure you got all the air out of your system then I'd say you got a bad replacement MC, which isn't unheard of.

[FORDification]

Bench-bleeding the MC is a mandatory step when installing a new one, and is a step many tend to forget (or ignore).