Ask the Editors: Dragging Rear Brake
Heated situation.
Let’s start with the good news. Hydraulic disc brakes work upon the exact same principles whether they are found on your ATV, automobile, motorcycle, mountain bike etc.
What you describe is known as brake drag and you are wise to address it as a buildup of friction heat can damage the pads, rotor and caliper, resulting in a very costly repair.
Start diagnosing your problem at the most basic- the caliper isn’t retracting all the way. A very common reason for this is low or broken down brake fluid. Also air in the brake line can cause this too. Replace the rear brake fluid and perform a bleed on the line. There’s a good possibility this will solve your problem right off the bat.
If it does not, it may be time to check the caliper itself. The following guide should give you a good foundation on doing some checks and maintenance common to all hydraulic disc brake setups.
