2014 RT rear brake caliper over heating?

[tleonard]

At 13,000 miles the rear rotor dished. I replaced the rotor, installed EBC pads, and did another fluid flush. I've never paid attention to the caliper temperature before but I noticed the new bright silver rotor got dark within 20 miles on the first test ride. So I checked and it got hot to touch - about 125 degrees. This is with no rear brake use and minimal front braking to slow for the driveway and come to a stop. The front brakes were cool, maybe slightly warm. My thought was to bed in the new pads and rotor so on the next test ride I used the rear brake many times at several minute intervals. The caliper got very hot; into the mid 130's. Yesterday I went for a long multi hour ride and with no rear brake use and minimal front braking the caliper and rotor stayed warm. Around 100 degrees. The caliper slides easily on the well lubed pins. The pistons appear to extend and retract as they should. New fluid - everything appears normal.

Is there normally that much friction that the rear caliper runs warm to hot as I'm experiencing and I've never noticed? Or is something else up; pistons not retracting quite enough or some issue with the linked proportioning system?

 

[52184]

If the pistons are retracting normally, brake fluid is reasonably fresh and well-bled, and the rotor isn’t dragging with the bike on centerstand after a short ride, I wouldn’t worry about. 130F is just not that hot, some light discoloration of rotors is not unusual, especially with certain pad compounds, and there’s always the chance that the brake is being inadvertently applied while you’re riding along. With a size 13 foot I have to be aware of that on all my bikes…

Best,
DeVern

 

[pglaves]

A remote sensing point and shoot thermometer saves wear and tear on fingertips.

 

[lee]

Don't forget the back brake is being applied every time you use the front brake.

 

[tleonard]

Yes, I've been super careful to not be riding the rear brake with my big feet. I've been using a thermometer after toasting my finger the first time.

Has anyone felt their brakes after a ride? My front calipers are usually cool to warm (70-80 degrees) while the rear is quite warm to hot (around 100). Is this normal? Thanks.

 

[ccolwell]

Have you tried stopping mid way through a long ride, putting it on the center stand and checking if the brake is dragging?

 

[51797]

How much travel do you have on the rear brake lever before you feel some resistance? If the adjustment is too tight, it may be dragging slightly all the time. (DAMHIK)

Frank

 

[lee]

Has anyone felt their brakes after a ride? My front calipers are usually cool to warm (70-80 degrees) while the rear is quite warm to hot (around 100). Is this normal? Thanks.

One time I thought I had a problem with the back brake dragging on my K1300S. The back brake was always hotter than the front when out for a ride and coming to a gentle stop.
One time I made a point to not use the brakes and coasted to a stop. That time the back brake was much cooler.

 

[tleonard]

I've never messed with pedal to master cylinder freeplay. I'm not sure what it should be and the Hayes Manual doesn't go into it. With a good push the rear wheel will spin almost 1/2 revolution. With so much mechanical drag it's hard to tell how much is attributed to brake drag. You can hear the pads dragging; similar to the sound at the front calipers.

I can wait and see how the heating evolves with additional use. I'm just mad at myself for not checking the temps over all these years prior to having this brake issue. I don't have a baseline as to what is normal.

 

[pglaves]

I'm just mad at myself for not checking the temps over all these years prior to having this brake issue. I don't have a baseline as to what is normal.

Baseline on one bike may be vastly different on another bike. There are lots of variables. Linked brakes? Disk diameter? Disk thickness? Type of pad material?

So get a baseline when you get a bike and then see what if anything changes over time. I recommend every rider own a remote sensing thermometer as a basic tool. Brake disk, final drive, transmission, exhaust pipe, and other things are all good to establish normal temperature ranges.