Topic: Well, I Posted In The "Dumb Things-What Have You Done And Now I Find This.

[bill440cars]

This was on my 80' CB750K

         When I was taking the broken brake rod off, I realized that the rear brake cam was pretty stiff. So, I took that apart, got it all freed up and back together. Got a couple of possibilities for that brake rod. Also, need to take the front brake caliper off, clean it up and make sure it is cleaned out real well before putting back together. My master cylinder does something I'm not sure why. After it sits for a while, I try to operate the front brake and there is no play in the lever. It's as though the fluid is expanding and pushing the master cylinder piston out against the lever. Only thing I can come up with is that it might be getting air in the system, but I'd think that it would feel somewhat spongy. Any input on this?


                              Thanks, Bill

[nickjtc]

Perhaps the piston down at the brake end is sticking in its bore. Once the lever is pumped a few times it works a bit, but when you let the bike stand for any time it seizes up again....corrosion maybe?

[bill440cars]

Perhaps the piston down at the brake end is sticking in its bore. Once the lever is pumped a few times it works a bit, but when you let the bike stand for any time it seizes up again....corrosion maybe?

          Yeah, there's no telling how long it's been since the system was serviced or anything. It's a 1980 model and may not have EVER had any brake work, who knows. I'll just give it a good going over and be done with it.

                                       Take care, Bill

[nickjtc]

I had the same 'wooden' feeling on Sophie before I overhauled the brake (new old rotor, cleaned out the accumulated cack from the master cylinder, new seals and o-rings, stainless lines). Although it made the front brake better than before it still bears absolutely no comparison with a modern brake. Don't get too excited, Bill!!

[DarkRider]

Both of you would probably benefit from using a newer M/C. When i posted the question about improving the brakes someone suggested using an M/C off of a newer Nighthawk. That or even using an M/C from a modern bike along with braided brake lines. 

[CBGhia]

I think i am going to start looking for a way to put a modern front otor and caliper on the bike.  My ducati Monster only had 1 front rotor, but it stopped quick as hell.  I want to try to have something like that with this bike.  It won't be quite as good I am sure, but I am scared that my throdle arm it gonna write a check my brakes cant cash.

[nickjtc]

Ditto. The front brake on my KLX250 embarasses Sophie all the time.

[DarkRider]

If i remember Big jim had something going on using RC51 rotors on stock hubs...and if i remember right he has a CB550.