This weekend I slam into a mountain on my bike.......minor damages to the right side fairings but what im stump on is my front brakes......visually checking my front tire i could see impact from the mountain on my tire, my rim, and my right brake rotor. Right now if i pump my front brake lever I can feel the pressure......but if i roll my bike forward or backward it releases the pressure from my brake level....if i park my bike and pump my front brake level again the pressure holds.....movebike fowardthe pressure is gone....i've gotton different opinions from people i ride with....but still tryinng to troubleshoot the problem....some belive its the rotor....some believe its the master cycliner....and some says it the caliber.....what ya think it is.....??any help will be grateful

 

you leaking any fluid? sounds like your MC isn't holding any pressure. even with a bent rotor, the MC should still lock the brakes up regardless as long as you're squeezing the lever.

try bleeding it first.

 

First off, you shouldn't have to pump any brake lever. When you grab it, it should hold right away. If you have to pump, you are either low on fluid, or have a MC problem. (assuming no leaks anywhere)

 

I have the same problem, though mine was caused something different. I pulled off my front wheel to change my tire myself (with the help of a buddy). Obviously removing/installing a tire without a tire mounting machine is tough and requires alot of man-handling. Anyways I had my wheel bolted to a shop bench and managed to get my new tire on, and back on the bike. What I didn't realize is that in the process of pushing/pulling/prying we managed to bend one of the brake rotors. As a result, the rotor sits slightly off of center in one spot. When you are at a standstill thats ok since when you pump you brakes the pistons compensate, bridge the air gap and clamp down on the rotor. Once they are pumped up the brakes feel solid. BUT, once you start moving again,the uneven rotor starts to rotate and push back on the pads as it "wobbles". This drives the caliper pistons back creating an air gap between the rotor and the pad again. This air gap near to be closed using a couple pumps of the brake lever. I'm in the process of acquiring a new rotor...I'll let you know if it fixes the problem.

My $0.02,

Matt