Servicing a Shimano Deore XT M615 brake caliper
These calipers are getting old-skool and Shimano never provided service parts anyway, but here are the details of the piston and seal in case you want to find alternatives
The Shimano Deore XT 2-pot M615 hydraulic brake caliper is getting quite old. Spare parts were non-existent even when they were new. Here are the details of the piston and seal in case you want to try some similar.
The piston is: 9mm deep and 20.95mm diameter and appears to be very hard black plastic, like bakelite. I guess it could be ceramic.
The seal markings say it is: 21.1 x 25.3 x 1.9. The caliper say the same ID and OD measurements in mm. Other markings are: IUY, 1.4 and NOK.
The seal is a square-cut O-ring, flat on three sides but has a square grove on the bottom side that faces to the bottom of the piston well.
