[et cetera]

I've been having an issue on my 78 SC after overhauling the brake system.

I rebuilt calipers, replaced the rubber lines with SS, put in a new master cylinder and had the brake booster rebuilt. I also put in new pads and rotors.

First time out I didn't notice any problems. Second time I did a bit more driving and once the brakes heated up they completely locked up, as if someone was standing on the brake pedal. I read around the forums for a bit and saw suggestions that you need to "exercise" the pistons in the calipers. So I did that an re-bled the brakes.

Out for a drive, everything is feeling great... Until I brake hard. They release a bit, but it causes the fluid to heat up again to the point which it locks up. I have to walk home and start researching again.

This time I take a look at the brake booster, I want to make sure I'm getting full travel on the pedal mechanisms. Everything looks good there, but I notice that the pin on the booster has a few spacers. I remove those to effectively shorten the pin and give me more travel with the master cylinder.

Out for another drive. Things are feeling good. I'm able to do a good amount of hard braking with out any issue. But eventually things start to lock up again. It releases a bit and I immediately head home, using the brakes as little as possible.

Now I'm just a bit lost. The only other thing I could think of is the master cylinder. I'm wondering if I didnt bleed it well enough and there is some air trapped in there, but I'm not sure that would cause this type of a problem. I'm also wondering if the new MC is just defective. I dunno.

I'd love to hear your opinions/experiences. I went as far as I could with the info I could find on the forums.