rear brake rotor heating up

[tab1324]

I recently rebuilt my rear brake master cylinder on my 79 and I also rebuilt the caliper. I've noticed however that when I stop and get off the bike, I still have a warm rear rotor even after not really using it. I check the wheel bearing area to see if it's transfering heat and it feels fine. I put in new pads when I rebuilt the caliper too. I know I'll probably get comments on making sure the return hole in the master cylinder was cleaned but I'm confident that it's good to go. Any other things this could be?

Tom B.

[GNEPIG]

.. the lever free play adjustment? the instructions are in the good book of Clymers.

[TopCatGr58]

Hey Tom,

Did you check and adjust the push rod that the rear brake lever is attached to that goes into the rear MC? Did you pull off the rear foot lever from the shaft, and relube/grease it to ensure that it fully returns to the up position? Are you possibly hitting the lever with the heel of your boot when they are on the footpegs?
Did you grease the slides that the caliper fits into so that it moves sideways easily?

There is supposed to be "some" small amount of drag and so it will still get warm, even hot, too hot to touch. Hope this helps?
T.C.

[HobbyMan]

Does the rear wheel spin freely? Put it on the center stand or lift up the rear end by a method of your choice. If it does, than it isn't the MC not letting off pressure. My rotors get pretty hot even just going around the block. Granted, I do drive a little fast.

[xschop]

check the "spooge" hole

Mine originally did same thing. Look at the M.C. spooge hole tip....

[tab1324]

yeah, TC there is a slight bit of drag and I was wondering if it was just "OK" as it is... I'm starting to think that it is if it's ok to get warm "even hot - too hot to touch".. I put in on center stand and it spins and you can hear the drag but it doesn't seem eXSessive to me.

Tom B.

[HobbyMan]

It should be free spinning. There should be minimum drag. If you give it a spin with your hand. It should spin for a full revolution at least. If there is drag, like everyone said, check the "spooge" hole. If that doesn't solve it, rebuild the calipers. Or at least take them apart and clean them.

[Shuriken]

I misadjusted mine years back. Then I took my girlfriend for a ride. A couple of miles up the canyon road, it locked up tight and turned red hot. Walked for a couple miles, flagged a cager, borrowed a wrench, bled some fluid, drove home. Girlfriend was pretty thirsty, as it was a hot day.

All because I misadjusted the rear brake.

DOH!

Ben