Hey Guys, I just finished a non-power drum to power front disc swap on my 70, additional thanks to Z-Mans 67 for his wrench turning abilities graemlins/thumbsup.gif I bought a kit from Classic Performance Parts and am pleased with how it all came together. After bleeding the lines and mounting my tires I find that the outer pads are rubbing on the rotor. My left front wheel is very hard to turn by hand, and you can hear the passenger side rub. I'm pretty sure I have the brake pedal hooked up correctly and the adjustment all the way down to the backing nut closest to the master. I removed my caliper on the right side and then re-mounted it no difference. the inside pad has about 1/16" clearance but none on the outer pad. Any help or direction is appreciated. thanks, Rob

Have you driven the car yet, there will be almost no clearance between the pads and the rotor after it is driven.

Yes the car has been driven approx 1 1/2 miles with the brake rubbing and heating up. even a little smoke. I noticed when I mounted the wheels that it seemed a little tight (brake pad) and figured it should be that way and will wear the first micro's off during break in but this is too, tight.
Rob

ttt

Are they floating calipers?
A little rubbing would probably be OK, since the pads will wear and even out. Did the instructions say anything about using washers to position the caliper squarely over the rotor?

Andrew

Andrew, I would assume they are floating calipers as the outer pad just rests on the mounting pin, which threads into the inner portion of the caliper. I found that after applying the brakes I can spread the pad from the rotor using a pair of channel locks, but as soon as I apply the brakes again it hangs up against the rotor. It looks as though the single piston is not fully reseating after letting off the brakes.
One other thing is my new porportioning block has a little rubber end piece in it on the same end that the two front lines attach to. The Chiltons manual mentions a metering valve that must be depressed while bleeding, could this be it? If so do I press it in only while bleeding the fronts? My kit instructions don't mention having to do this. Thanks again,
Rob

Did you lube up the caliper pins? Just a shot in the dark. As far as the rubber button on the proportioning valve. It's a purge type deal. If you think about the bore in the valve, there is a small area in the end where air can be trapped and you'll never really get a GOOD pedal feel. So pressing the pin in the end of the valve allows the air to escape.

Originally posted by jpete:
Did you lube up the caliper pins? No I didn't lub the pins. Should I have? Seems as though dirt and grime would gather there, and cause problems later. I will try purging the block though.
Thanks,
Rob

I did this conversion and ran into the same problems you have and i will tell you what we did to fix it, not sure if it was all these things or just a few.

The brakes would rub on the car and found out there is a DIFFERENT proportioning valve for DISC/DRUM then there was for my original DRUM/DRUM. Replaced that and it made it better but still rubbed. Could still sit @ a light when the brake off and not go anywhere (automatic).

Then i went through about 4 master cylinders before i got a good one and thats what fixed it. DON'T BUY FROM AUTOZONE, the one i got looked TOTALLY different then the one from autozone. I bought it @ carquest. Anyway i wish you luck i know how frustrating it can be.

Originally posted by 17Again:
</font><blockquote>quote:</font><hr />Originally posted by jpete:
Did you lube up the caliper pins? No I didn't lub the pins. Should I have? Seems as though dirt and grime would gather there, and cause problems later. I will try purging the block though.
Thanks,
Rob </font>[/QUOTE]Someone said "Don't buy from AutoZone" and in many cases that would be correct. But for disc brake grease, go look on the counter where they keep the little pouches of dielectric grease, anti-seize, and brake grease. They are about $.89. Just smear a little on the pins to help the O-rings in the calipers slide. No need to glob it on. I like to be able to slide the caliper back and forth with just a light touch. If you can do that, look some place else for your problem.
As far as holding that pin in, you're supposed to keep it pushed in while you do the "Pump the pedal" procedure. Don't ask me how to do that, because I never have :D If you vacuum bleed the brakes use a rod braced against the seat to just slightly hold the pedal down a bit for the same reason.

Good luck
Jeff