yesterday I noticed my rear brake pads being completely worn out at 44000 km. Last time I checked at 35000 km and they were fine. The brakes were dragging a bit at that point so I cleaned the caliper and pistons and did all the sliding pin maintenance. The brakes were still slightly dragging afterwards but the rotor didn't feel hot to the touch so I left it at that. I can't tell if that has changed in the meantime.
I don't use my rear brake much and don't rest my foot on it. I recently filed down the rear brake push rod at 42000 km to lower the brake pedal (see this thread: Rear brake pedal adjustment bottoming out after foot peg...
) and tested the brake pedal forcefully on several occasions.
Today I took the caliper apart and noticed wear on the piston on one side only.
pads good at 35000 km
Top Piston seal bit dirty but looks ok, bottom seal seems fine too
Oooops, I wish I hadn't pushed it back in.....
brake fluid from the calliper quite dark, last flush 8 month ago
Only in the photo the damage was obvious to me, just looking at it I could easily have mistaken it for some stubborn crud
opposite side looks better, just some very hard to remove crud?
Did the piston get stuck and could only move back on one side which caused the damage? I'm trying to understand the mechanics of it...
Could my modification to the push rod have anything to do with it?
How likely is the piston responsible for my woes?
Could I be ok using the old piston and new pads and just see if the rotor gets hot?
I'm going on a 6000km trip to Greece soon. I'd be happy if anyone could share their experience with brake and piston wear...