Motorcycle Repair: Master Cylinder - Honda CB750k, front brake caliper, caliper pistons

Question
Hello Chris,
I have a 1979 Honda Cb750K which I have rebuilt the front brake caliper as well as the master cylinder with a new rebuilt kit. I have bled the system several times now and all fluid looks free of air. My problem is that I will have brakes but they drag and get warm. The brake lever has built up so much pressure that I barely pull on it to engage the brakes fully. It acts like the fluid is not returning. Very little play in the lever with a lot of pressure. When I put my brake bledder line on the bledder nipple I have nice pressure on the handle and I can see fluid pumping out of the bleeder then back in when the handle is released. I can also see the reservoir lowering and raosing like it should. But once I put the bleeder nipple back on then the handle gets extreme pressure again.
So I'm not sure if my problem is in the caliper or the master cylinder.

Thanks for any info you may have!

Ken

Answer
Hi Ken.

When you rebuilt the master cylinder and caliper, did you clean them both out completely (including making sure the caliper pistons were polished and clean) as well as pressure flushing the brake line (or, ideally, replacing the brake line)?

I have a feeling that something was not cleaned out properly, causing sticking in the system.

Completely disassemble and check the entire system and I am sure that you will find something that you missed before or something misalligned.

Good luck and ride safe.
FALCON