I'm heading to CO next Thursday, and it appears my rear brake is mostly non functional. It worked before taking the wheel off for a tire change, the bike sat for two weeks waiting for the tire to show up, now very weak brakes. I tried new pads but no result. It doesn't really build pressure after pumping. I did try reverse bleeding and didn't notice a difference. Due to time constraints, I may not be able to get a master rebuild kit ordered and installed. Anyone know if they are just orings inside the master, or if they are cup seals? It's the only thing I can think of to change.