Question on rear brake adjust

[d3vi@nt]

I read all the rear brake related problems so I could avoid them... and then didn't.

I swapped the stock P32 calipers for P34's on my ST2 to try to get better feedback from the rear brake. Bled it well, and left the lever compressed for 24+ hours. Felt very firm as it should. Wheel spun freely exactly as before.

PO had the lever too high, so I dropped it as low as possible per the shop manual (retract stop-screw on the brakelight switch mechanism).  Freeplay seemed as before, so I left as-is and the wheel still spun freely. I'm sure this was my error, though everything seemed to operate fine on the stand.

Couple blocks into my ride and the rear brake was dragging. Pulled over quickly and it was all but locked up. It cooled quick enough to unlock and I adjusted the lever back to its original spot to get home.

I'd still like to drop the lever back down so I don't have to lift my foot off the pegs to use it. Can someone please help me understand the proper way to adjust it?

I'm confused, as it was not dragging when on the stand and I activated the brake multiple times to make sure the pistons returned properly and didn't stick. And I wasn't using it, so I'm sure why it behaved this way.

I understand the top screw going to the master is where to adjust for free play, but not sure which way to turn and/or how much.

Any help appreciated!

[Buhgaboo]

Sounds like the pushrod isn't letting the fluid return...it heats...expands...pushes on the pads...seizes on the rotor...the pushrod has to have 1-2mm of free play...the angle adjustment is done in whatever manner that allows for the pushrod to maintain the 1-2mm of free play...without the free play the return port is blocked and well you know how it ends

[d3vi@nt]

Thanks for the explanation.

Question then; how does one adjust free-play?  Obviously start by loosening the jamb nut, but I don't find a way to rotate the pushrod. I see no slots, and nowhere to grip that isn't threaded.

And then the dumber question... which way to turn it to increase freeplay?

[Buhgaboo]

Clockwise turns the push rod into the brake master cylinder...counter clockwise will pull it out...the free play can be felt by pushing the brake pedal down and pulling it up...with your hand touching the pushrod you will feel it hitting the plunger inside the master cylinder

[Howie]

Shorten it.  Err on the side of too much.

[d3vi@nt]

Thanks, guys.

I realized the little hinged clamp allows for pulling the pin out of the fork at the end of the pushrod. Seems obvious now, but wasn't sure.

I couldn't clear the forked-end from the brake lever to turn it. Only way I was able was to remove the brake lever. Seems the only other option would be to remove the master, but the brake line wouldn't allow for much movement.

Is there a better/easier method to turn the rod?

[Buhgaboo]

It's probably a lil seized in the threads...penetrating oil and heat...my pushrod has a tiny flat for a wrench to help apply some torque but I can spin mine by hand with the jam nut free