**How to get that last little bit of air out the line**

Quote:

Originally Posted by Duane S.

Regardless of what type of handbrake you have, take an minute and read this. If it isn't rock solid the first time you grab it, this will help.

Don't take anything off the handlebar mounted master cylinder (leave the line on), Take the master cylinder off the bar and hold it right side up. Hold the lever in one hand and the master cylinder body in the other. At this point you want a friend holding the reservoir cup above the master cylinder w/out the cap on. Continuously pump the lever with all your strength, changing the position of the master cylinder to give the air every opportunity to work it's way up from the top of the line into the master cylinder. Brake fluid is easy to seal compared to air. As you pump the master cylinder, you will be forcing the air past the primary seal in the master cylinder (the seal in front of the piston) so it is behind that seal and in front of the secondary seal (the seal on the back of the piston).

Now this is why you want to have your reservoir cap off and above your master. It is entirely possible that as you were doing this you were seeing air bubbles emerge into the reservoir up from the tube. If you did not, at this point you will.

Take the tube between your thumb and two fingers and pump the reservoir tube. When you squeeze the tube you are forcing fluid down into the master cylinder and causing turbulence. When you release the tube the fluid is sucked back up into the tube that you've just displaced. Along with the fluid, the air will come up the tube as the turbulence you've created in your master cylinder has broken the air bubbles free from the sharp edges inside of the master cylinder that they were clinging to (sort of how bubbles cling to the inside of a glass) and now want to float to the highest possible point which is inside your reservoir cup and into the atmosphere.

This why people can say "I've bled two bottles of fluid through my handbrake and it still works like crap". You could bleed a 55 gallon drum of fluid through there but as long as you don't get that last little bit of air out of there it will never work right. Do not crack any lines when you do this. Repeat the steps until you stop seeing air bubbles and your lever is rock solid. You'll be amazed that the transition between foot to handbrake is no longer an issue ( as for giving the hb a pump).

I did not write this Bill from FTI wrote this but I used this alot and it works everytime