I have fitted disc brakes (r31 skyline front and Bluebird at rear) and my front discs are not releasing completely. The back brakes are fine. If I pump the pedal a few times the front wheels seem to get hard to rotate - what have I missed? I just using a standard 1200 master cylinder with no booster.

Being a 1200 drum brake master cylinder it would have a line pressure valve in it,you have to remove it or get a 120y disc brake master cylinder.should fix your problem.GREG

Thanks Greg - but the master cylinder used was a 120Y which had front discs and rear drums. I've now got rear discs but it's the front discs that a binding. Excuse my ignorance but where is the line pressure valve? thanks again

The valve is just behind the front brake pipe conection on the master but the 120Y wont have one .
It may be the rod under the dash is out of adjustment which is holing the brakes on ?????
Pedal should have a little clearance between it and the rod.GREG

Were there shims(spacers) behind the old master cylinder when you removed it? They will probably have to go back in. As Greg said, need a little freeplay.

Remove the caliper pistons & check for pitting. If the pistons are pitted you will need to replace them & all the seals in the calipers.
Coops