Bill McMahon

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).

DoodleF4i

+1...bleeding brakes is p retty easy..i dont know why so many stunters have problems with it.

chirpin4th

sticky this ****!

E-Loc540

something else that may help...take your caliper and brake pads off and have a friend hold the master and reservoir just like Bill said (with the cap off the reservoir) now squeeze the caliper piston all the way in (this may over fill the reservoir) this will also help air that is hiding in the creveses to push back until it exits the system. While you have your caliper off grease the pins too....

nags

Awesome post

Darius

Bill I've been doing everything you just said from day 1! Air is the enemy and I will defeat it:YEAH

Big R 508

I've been havin a problem w/ 929 & 954 HB which it doesnt allow air come out so finally I got 06 636 radial master ( very easy to bleed ) problem solved , never had problem after that.

powder46

solid info BOSS!!!

Ryan Moore

Demo Video!!! toss a little clip together and it will make alot more sense to me and probly many others. I put my bike on its side before I ride and pump the master a bizzilian times and watch bublles float up the line every ride. Could that be from runnin a capped off line instead of a resi, I love not havin the resi on the bars, way more room for HC tricks.

NINER

Tapping the master with a metal object helps this process as well.

Bill McMahon

That's what I'm thinking Ryan. Stuntfest is in just a week and a half, I'll put one together there.

Niner, +1 on the tapping, anything that breaks the surface tension of the bubbles so they float to top!

Ryan S

bill: very good advice


HOWEVER,


THE BEST WAY TO BLEED A HANDBRAKE IS TO ZIP TIE YOUR LEVER TO THE HANDLEBAR OVER NIGHT---i never would have thought this would work, but i bleed all my brakes like this now.....WAY easier and my hb is rock hard.

eazenutz33

I've done that before and it seems to work good 99% of the time, especially on my stock F4i front master, but on my 600RR handbrake I had to bleed it closer to how Bill said cause there was a pain in the *** airbubble that didn't raise up with pressure, even overnight. I've let air get back into it so now I gotta do it again , OR I can ride my F4i...............hmm, I'm lazy, looks like I'm riding the F4i

Bill McMahon

Good stuff Ryan, but if the air is at just the end of your line at the master cylinder banjo bolt, or is past primary seal in your master cylinder and just can't get out becuarse the reservoir inlet is upside down (as on most bikes using an upside down front brake master cylinder), the air will still be there the next morning when you take the zip-tie off.

HOWEVER!!!! This step can't be ignored as the last step to get every little bit out of your handbrake once you have taken the master off of the bar to give the air at the end of the line and in the master cylinder the opportunity to exit out through the reservoir cup. I do this too and am embarrassed to have forgotton it.

3824

good stuff bill

excessa

I have such a crush on Bill McMahon.

John LegionST

Great advice Bill, thanks!

And for anyone that doesnt already know this... do yourself a favor and go to an auto parts store and buy a vaccuum pump... by far the easiest way to get a dry system full of fluid!!! and it gets almost all the air out very quickly... then you can ride and little, bleed it some more, do some of the great tricks/techniques like this one that you read on here, and your HB will be 100% solid!!!

dizzie56

+1 on the vacuum, air comes right out after runnin it thru a couple times. took me bout 20 mins tops to do my clutch and my rear brake.

GAMstunts

I bled mine according to the instructions included with my rear master Bill sent me. HB works great and I only got a gsxr upper master.

GAMstunts

+ 1 on vacum