I have a 96 suzuki bandit, I just replaced rear brake pads and rotor. I noticed that after a short ride, like a mile, the rear brakes get very hot even if I don‘t touch them. The old pads had one that was worn to the metal and one that had little wear, do I need to rebuild the caliper or is this perhaps normal, I never felt how hot the rotor was before. I think I was fooling myself into thinking that the caliper was alright, but now I‘m doubting it‘s ok. Does the caliper need honed to be rebuilt or just replace the seals and that‘s good, I‘ve never done a motorcycle caliper before and my manual is a little sketchy on this topic.
if it,s as bad as you say then the lines will be contaminated also !
Caliper or like Mike said Master. Either can cause dragging pads. If you find pitting of the caliper body or piston it's time for replacement. Ditto for the master. Don't scrimp on brakes and change your damn fluid at LEAST once a year!
The caliper piston is sticking and making the pads drag, hence the heat. Remove the pad, pump the brake pedal carefully to push out the piston (but NOT all the way!). Get some brake cleaner spray and give it a good squirt. Push the piston back in and reinstall the pads and caliper. If it continues to get hot, the piston bore may need a hone. If you go this far, you should replace all seals etc whilst you have it apart
I agree with molitor on changing the fluid. Brake fluid is hygroscopic and attracts water like a magnet. Here's what oftentimes happens; over the years the old fluid attracted so much moisture the water falls out of suspension. Since water is heavier than brake fluid, the water collects at the lowest point in the system, the bottom side of the brake cylinder and corrodes the metal. As the pads wear, the void in the cylinder becomes greater. You install new, thicker pads requiring the piston be pushed back into the cylinder. The piston now covers the area of the cylinderwall that was exposed and became corroded. the corrosion causes the piston to bind up. When you apply the brakes, you apply enough pressure to overcome the resistance, however when you release the brakes, there's nothing to force the piston back, leaving the breaks partially applied. To rebuild the calipers, but new seals (one per piston), remove the caliper from the fork leg (if the front) and suspend it over a container and pump the brake lever until the piston falls out, letting the funky old fluid run into the container. If the piston is rough, use fine steel wool to polish it up as well as the inside of the brake cylinder (after removing the old seal). Clean things up well, lube with new fluid and reinstall the piston. Pump all of the old fluid from the master cylinder and reconnect the caliper and install. If on the front, remove the opposite caliper and pump the lever until that piston comes out. Don't try to use a brake hone that has stones because those are made for cast iron cylinders. Aluminum will clog the pores of the stones and render it useless. Keeping the fluid changed will ensure many years of trouble free service. I've kept the fluid changed on my KZ 1000 and other than replacing pads and switching to braided stainless hoses, I've never had to service the calipers or master cylinder in 30 years and 115,000 miles.
