Need help: Shimano XT brake blocked after oil leak and piston over-extension
Hello everyone,
I need some help setting up my hydraulic Shimano XT brake (2-piston system). My current problem is that I cannot get the wheel (with the brake rotor) back into the frame/fork because the brake pads are sitting too close together.
How it happened: My brake was rubbing slightly, and I wanted to adjust it. Unfortunately, I accidentally loosened the wrong bolts on the brake caliper. As a result, a large amount of mineral oil leaked out, and I suspect some of it might have contaminated the brake pads (though I'm not entirely sure).
Afterward, I refilled the system with mineral oil because the bite point was completely gone. While refilling/testing, I pulled the brake lever as a test—however, the wheel was out at that moment. It seems the brake pistons extended way too far and are now stuck in that position.
My questions for you:
- Can I safely push the brake pistons back into the caliper? What is the best tool to use for this without causing any damage? (The pads are currently still inside).
- Since this is my very first time repairing anything on my bike: Is there anything important I might have missed, or are there steps (e.g., proper bleeding or replacing the pads) that I absolutely need to do now?
Thanks a lot for your help!