Front brakes sticking - what to do next?

[Spyderman]

Hi all,
My front brakes are seizing, so my first point of call was the flexi lines, as this is the usual reason. However, I have replaced these, and the brakes still stick! My next point of call was the callipers, so I have now replaced these as well... Still stick on... I've now removed the master cylinder, but this seems to move freely and returns just fine.
I'm probably going to replace it anyway, now it's off, but I can't work out what the problem could be!
Could there be a problem I can't detect with the master cylinder?
Could there be a problem on the rear circuit that manifests itself by making the front brakes stick (whilst the rears don't appear to stick)?
Any ideas welcomed
Cheers,
Timo

 

[Spyderman]

Oh yeah, and I've checked the free play on the pushrod!

 

[71Westy]

The Bentley manual references a small bypass port in the master cylinder thast when blocked can cause binding...

Nick

 

[Spyderman]

Oh cool, Hopefully it is the master cylinder then - I have a new one to fit later, so fingers crossed!

Cheers!