Front disk brake dragging!

[Excess Impulse]

Thought I should post an update to my brake problem as I have resolved it. I apologize for taking so long but must admit Im a little embarrassed as the issue was not the new brake line, new caliper piston and seal, nor was it the master cylinder. It was me, and an assembly error. I had put the little tension spring that holds the pads onto the pin in between the caliper and the inner brake pad, preventing the pad from moving away from the disk. Once I noticed this it was a 30 second fix and I am happy to say the brakes function good and I am finally on the road and enjoying the ride!

 

[Scorpio1963]

Well simple enough I know my fix is going to cost $ some extra I dont have right now.Im trying to get the beater in top shape and some side work as popped up so Ive been rather busy.

 

[Jakwub]

Sorry to revive a 5 year old thread but I had this same issue on a '77 XS400D hat had been sitting for years.
The solution for me was to take off the master cylinder, remove the screwed down & pressed on tank, and flush every hole I could find with brake cleaner. Jeff0133 was right in my case that the vent was clogged.

For good measure I also went through the caliper, popped the piston out and cleaned everything thoroughly. To be clear though, the caliper cleaning was not the root issue since the front brake was still sticking before and after cleaning.