Just finished working on the front brake and this is what I did.
Removed the caliper for inspection and cleaning. These brakes are very easy to work on. They are so accessible, you can limit your work to what is needed. The often repeated argument 'now that you're on it', doesn't hold here. Prior to disassembly I had put some penetrating oil on the thread where the pipe enters the top of the caliper, repeated for a couple of days. Don't be tempted to try an open wrench to undo that nut. Use a vise grip instead. Same for the bleeding niple's hexagon. After removing the seal, I dipped the the caliper (left part) in a friend's ultrasonic bath. The piston - in spite of its 47 years of age - can be reused. There is some minor pitting, but it's still the same I have seen some 20 years ago. To be sure I showed it to two mechanics and both said it can be reused no prob. Renewed the seal.
I did not replace the brake hoses. I check them at the beginning of every season and I have no indication for renewal. Maybe because my bike has always been parked in a dark garage. I doubt SS lines will be much of an improvement on a CB500/550 anyway: lines on these models are very short.
I did replace the master cylinder though. The old one was more or less eating itself and CMSNL has a good repro MC (45500-300-010P). Had heard the repro is even better than OEM and a price of € 55,- is unbeatable, if you realise a set for an overhaul is about the same amount. BTW, an OEM mastercylinder is € 532,- (!). The much prettier cap of the old, now abandoned original MC fits the repro nicely. Replaced the worn to the red line Honda pads by ceramic SBS 501HF*. I trust ScandInavian products. The A pad comes with a very nice ring on its back. Smeared an ultra thin (!) coat of copaslip on the sides and backs of the pads. The caliper swing arm didn't need maintenance.
All is fine. The new brake pump has a very nice feel and the pads don't sqeal.
Tip: Forget about brake cleaner! Never liked the stuff. The result was always poor, leaving the disk somewhat greasy. I've used some denatured alcohol on sponges that can remove stains. Wipe the disk once more with denatured alcohol on toilet paper.
* For some reason I have not seen aftermarket brakepads that have these red indicator lines.
