SRAM level ultimate Service Manual page 20

7
Use a pick to remove the piston seal from inside both the inboard and
outboard half of the caliper body.
Spray isopropyl alcohol into the caliper piston bores, and clean them
with a shop towel, then install a new seal inside each caliper body half.
NOTI CE
Do not scratch the seal gland with a pick. It could result in a slow fluid
leak when the brake is applied.
Caliper Piston Removal 20