Gen5 2nd Master leak

Hi folks, my 2nd master brake cylinder (LHS F) is leaking....not severely, but bad enough.
For those of you that have experience, should I replace the piston set (4562MBG006/016) or do the joint set as well (45630MBG016/026).
Another option I found is the K&L Front Brake Caliper 2nd Master Cylinder Rebuild Kit 0107-099.
All suggestions gratefully received, reviewed and acted upon!!

(Moved from Gen5 forum)

 

Can you post a pic of exactly where it's leaking?

 

Also interested in what's actually leaking. The SMC if leaking should be rebuilt, it's old. Will not hurt. Not uncommon on ST1300's with similar if not same SMC. OEM or aftermarket, I have no experience with K&L, I'd be biased toward OEM.

 

K&L is decent stuff and is one of the only non-OEM options I'll use.

 

I bought a full master kit with new piston. Installed, and it's leak free ever since. Combine with stainless braided lines in front only, and the braking feel is great. No desire to de-link now.

Jose