I noticed that the rear disc on my Eglide (with ABS) was very hot to the touch on my last ride of the season, much hotter than I thought it should be. This was just after having the dealer replace the brake fluid.

I was doing the winter-once-over recently and after removing the rear wheel I found that the outer edge of the rear brake rotor and part of the disc face had turned an amber or gold color. I checked the pads and both seemed to be evenly worn with about 1.5 millimeters or .006" thickness left. I suspect the gold color is due to excessive heat. The only heavy braking came with a panic stop earlier in the year that resulted in a minor (low damage) rear-end collision last summer.

So I have a couple of questions. What would cause the excessive heat? Pads dragging on the rotor would seem to be one reason. What would cause the pads to drag? I realize that there is some rotor pad contact in normal circumstances.

How could I test for stuck pistons in the caliper. Would a slight push on the brake pedal work to see if they move. This makes me a bit nervous since I don't want to push the pistons out of the caliper. I'm out of my depth here and would be grateful for any help.

 

You may have a piston cocked in it's bore. Does your cruise control still work?, Is the brake light on all the time, that is usually a good indicator.

Use a putty knife between the brake pad and rotor and move the piston back into the bore, apply brake and repeat a few times while spraying brake cleaner on the suspect piston. Just sayin......

 

I reckon your hunch is right, dragging pads caused by a sticking piston in the caliper.
Brake fluid absorbs moisture which eventually leads to corrosion in the piston bore. This ridge of corrosion causes the piston to stick, especially after a pad change where the piston is pushed back into the bore to accommodate the thickness of the new pads.. This usually occurs on bikes with fluid that hasn't been changed or bikes that live in high humidity environments. How long ago was the last fluid change before the dealer changed it?

 

Sticking piston in there maybe. I had that happen a few years ago on me, was on my Shovelhead taking a ride into Rhode Island...on I-95 north she started laboring, felt like losing power bad, rolled more throttle on, she start slowing down...and then slowing down hard..and then the rear tire starting locking up leaving morse code marks on the highway. Worked my way over to the right lane then breakdown lane, by the time I ground to a halt..big smoke cloud caught up with me. Rear caliper 'n pads were smoking bad...like white hot. Rubber boots on the caliper pins melted.

Tried knocking it lose..nada. Waited for it to cool down enough, took out my toolbag and pulled the whole rear caliper 'n pads off..headed back home on back roads front brake only.

When I got home pulled off rear disk she was bowed out saucer shaped from the heat.

GET IT CHECKED.

 

check the bushing on brake pedal

 

Before you start tearing the caliper apart make sure your brake pedal is properly adjusted. A too tight adjustment can put pressure on the master cylinder which in turn puts pressure on the the caliper.

 

Bike was new in 2013 and had the first fluid change last fall.

 

If the piston is stuck due to corrosion what is the fix.

 

you clean and lube it. you can get in there and clean it up with the break clean and a tooth brush, then a little caliper grease on the pistons.

probably the bushing on the brake though. some of the older ones swell up.

 

It could be as simple as brake dust build up. Read post #2, KISS. Then move on to all the nightmare scenario stuff.