Topic: Cb750k 77 front brake piston?

[Jonm99]

Hi guys,

I am in the process of restoring my bike and recently took apart the front brake caliper for servicing. What I found does not look like what I had expected... It has a bizarre 2 piece piston. Is this an aftermarket replacement? Is it from another year/model? Or is the entire caliper from another year/model? If you recognize it, I would appreciate if you could let me know what we're looking at :-)

[Phinn]

I think my 78 piston was like that, but I didn’t disassemble the two pieces. The outer chrome was pitted so I tossed the whole piston out and replaced it with the phenolic.

[Marks78]

Not sure about your two piece piston but the piston on my '78 750K was one piece but due to rust/pitting I also replaced it with one of Godffery's (he is a member here) Phenolic pistons.  About $45 last year. Not sure if he still makes them. Google "Godffery's Garage". Best of luck!

[Jonm99]

Thanks, I'm on the fence about replacing the piston as I have no pitting, just not sure what it is I'm looking at 

[scottly]

That's not a stock K7/K8 piston.

[Jonm99]

Thanks Scottly, thanks everyone. That settles that :-)

[Johnie]

No pitting - you are good to go. Previous owner maybe replaced it.