I have the same problem. Need O-rings for the bleed nipple and also need a line clamp. One vanished somewhere along the way. I was told Avid sells a kit with replacement O-rings in the U.S. (part number BKPT50515). A local shop should be able to order them for you. I tried Lowes hardware and found some the correct inside diameter but they were too thick and I couldn't thread the nipple into the brake reservoir. If anyone has a line clamp laying around they want to get rid of I'd happily accept an offer to buy it. Not really keen on buying a whole new kit but my clothes-pin clamped with small vise-grips pretty much blows.