Hi guys, I have a problem with my front brakes. I've just swapped to a set of braided hoses and changed them myself. It's the first time I've ever done anything like this.
The thing is that the system keeps losing pressure, but it does it alarmingly quickly. There don't appear to be any leaks anywhere, well I can't see any anyway, and I've checked pretty much everything I can think of, including the discs, for good measure.
After each time that I have re-bled the system, if I roll the motorcycle forwards just a few meters, the pressure disappears and the lever will come all the way back to the twistgrip. Please help me, as this is killing me...
Hi K.Kim, fear not; there's likely a simple solution to your problem.
If all your checks are correct, then the only real possibility is that you still have air in the brake hydraulic system, which isn't rare when bleeding brakes for the first time.
The chances are that the air may be caught in a length of brake line that is somewhere above the height of the master cylinder. If this turns out not to be the case, then we'd bleed the whole system again and replace it with brand new brake fluid.
You don't say whether you used the original or new brake fluid, but if it was the original and any moisture has got in, then you could well end up with this kind of reaction. Replace the fluid and check the high spots – good luck
By: Anonymous: Tony () Monday, 15 August 2011 @ 07:00 AM ICT
I had a similar problem with my motorcycles hydraulic brakes, it turned out that the brake fluid I had was contaminated with moister. It doesn't take long for brake fluid to turn bad, if you leave your brake fluid can open for one night... it's bad the next morning. Most brake fluids are highly hygroscopic, hygroscopy which means that it attracts and holds water molecules.