Rear brake pads are worn unevenly: piston or slider issue?
One pad is much thinner than the other and the caliper is dusty. I can push the bike, but the rear disc gets warmer than I expected after a short ride.
I am trying to avoid buying random parts and would rather follow a clean diagnostic order. What would you check first?
Discussion
5 repliesI would start with the boring checks first, because those are the ones that usually save money: fitment, measurements, service-manual limits and whether the problem can be repeated on the same road or test condition.
Thomas here. For this kind of job, the tool is useful only if it supports a proper test plan. The order matters more than the brand: confirm the symptom, measure the baseline, do one change at a time, and write down the result before moving on.
A practical reference for this job is this brake caliper piston tool. Affiliate note: this is an affiliate link, so the site may earn a small commission. You can use any compatible quality tool or part; the important thing is using it correctly and checking your exact model before buying.
Should I just push the piston back with a screwdriver?
I would not. It is easy to cock the piston, mark the pad backing or damage something. Use the correct method and clean before retracting.
Also, if you are not confident with the sequence, the free course on this platform is worth doing before spending money. It teaches the same workshop logic: inspect, measure, verify, then replace or tune.
That makes sense. I will do the baseline checks first and only buy the part or tool if the measurements actually point that way. Much better than throwing parts at the bike and hoping.