I changed front pads a month or so ago and ended up with a spongy lever. Thought it was weird, didn't understand it, but figured it was a good opportunity to flush the system. With a fresh unopend quart of Bel Ray Brake Fluid, I commenced with bleeding that night via my trusted vacuum pump bleeder. I bled, and I bled, and I bled... level still spongey. Then I tried back bleeding with a syringe from the bleed nipple back up to the mcyl. I fiddled with it off and on for another week and ended up riding with substandard brake feel hoping the jostling of the front end would dislodge whatever air still stuck in there. No luck. I even tried the suggested zip tying the lever tight to the handlebar overnight... that worked for about 10 minutes. A week ago I had decided that I was going to tear down the master cyl and rebuild it, and if that didn't work I was going to replace the line. However , as a last ditch effort before spending money, I decided to remove the whole assembly from the bike and fiddle with it in hopes of dislodging the air. I held the setup by the lever, letting the caliper dangle and started "tapping" on the caliper with the rubber end of a screwdriver. I tapped all over the caliper, the line and the Mcyl. Did that for about a minute probably, then stuck a piece of flatbar between the brake pads.. two pumps and the problem seemed to be solved. Crazy stiff lever... THEN, I put it all back on the bike and BOOM, spongy lever. ARGH!!! Should I replace the line now? Rebuild the Master? Any other tips? Help!
Ahhh yes. I remember reading somewhere that the seals sometimes go bad and allow air to bleed into the system. Good call.
