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Hi guys.:hello:

Bleeding the master cylinder, i am not get a good flow of brake fluid. More bubbles than fluid:sad:. I am using a pump, repeat the process 7-10 times. I can still squeeze the brake a inch away from the throttle. I have good seal and suction.
But i am getting a good flow no bubbles on the two front calibers.
How do i get a good flow on the master cylinder?:dontknow:
 

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Pump the brake and hold. Then crack the bleeder valve (at the caliper) open. When the the lever goes in, hold it and close the bleeder valve. Or just get you a one man bleeder kit with a vacuum hand pump and a capture jar.
 

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Discussion Starter #4
i'm using the vacuum pump but still not getting straight fluid.i guess i need to keep pumping and filling.
 

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Once you get fluid at the calipers, bleed the master again if there is no lever pressure. most of the air will of gone back up.
 

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I know it sounds dumb, but do you have enough fluid in the reservoir?
 

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bleed the master first.

when I put new Galfer green lines on my 06.
I bled the left caliper first,then the right.
I manually bled mine,bled each caliper until no more bubbles came out.
Then I went to the master cylinder and bled the bleeder screw up there until it to was a steady stream.
Instant brakes,took me all of an hour install and all.
 

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i'm using the vacuum pump but still not getting straight fluid.i guess i need to keep pumping and filling.
Yeap... I changed brake lines in my bike recently and i finally made it...after 30 minutes. Sometimes it just doesn't want to finish quickly :lol:

Also sometimes the air is trapped in the hose that goes to the reservoir. Make sure to press it from time to time
 

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yeah i just did my brakes and im having the same problem.....

i can pull the lever about a half an inch from the grip and it feels KINDA soft yet hard..... i guess mushy.... the brakes do work... but i feel as if there is air still in the system

i bleed everything about 10 times.... no air bubbes coming out anywhere.... i dont know what to say... it just doesnt feel right
 

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Discussion Starter #11
yeah i just did my brakes and im having the same problem.....

i can pull the lever about a half an inch from the grip and it feels KINDA soft yet hard..... i guess mushy.... the brakes do work... but i feel as if there is air still in the system

i bleed everything about 10 times.... no air bubbes coming out anywhere.... i dont know what to say... it just doesnt feel right
i know the feeling
 

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bleeding

after making sure the lines are full with vaccuum pump leave it hooked up but dont draw vaccuum and then bleed using the lever to pressurize the line and watche the vaccuum hose for the bubbles to stop. I have the best luck doing calipers first then the master.
the last resort is to bleed by cracking open the banjo nuts with brakes pressurized use lots of rags to catch all of the fluid. this will require an extra set of hands.:thefinger
 

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so whats the best way to bleed the whole system.... left caliper right caliper master cyl.??? any advice is appreciated

sorry for the thread jack but i didnt want to make the 100000th thread on brake bleeding :lol:
 

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Another trick I read a while ago is after you have bled them, ziptie the brake lever to the grip really tight. Leave it over night and you should have rock solid brakes in the morning.

If not, bleed again and then try it again. I have done this in the past and had MUCH success. Something to do with forcing the caliper seals out a little and forcing small air bubbles into the fluid. Then when you bleed again, they should come out with the fluid.

I saw some very interesting things when I put the "fresh" fluid I bled out of my calipers under 20" of vacuum. Literally, the clear fluid turned opaque and after about 5 minutes, all these bubbles rose to the top making the fluid clear again! The air "dissolves" into the fluid and then expands when the fluid heats up or you apply a strong vaccum. Would have never believed it unless I saw it with my own eyes...:eyecrazy:
 

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One thing you need to try is with the bleeder fully tighted (or so you think) hook up the mityvac to one of the calipers and see if it is holding vacuum. I just did my lines on my 06 and noticed that with everything tightened up I wasnt holding constant vacuum. With that I was able to determine that the bleeder wasnt seated completly inside the caliper. I ended up swapping out the bleeders and viola!! I was able to get all the air out and a good feeling brake. What you are experiecing is the air entering the system at the bleeder so a complete bleed isnt possible.
 

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Another trick I read a while ago is after you have bled them, ziptie the brake lever to the grip really tight. Leave it over night and you should have rock solid brakes in the morning......

:
That there is one of the greatest misconceptions about bleeding brake systems. You will get a rock solid lever in the morning from binding your lever overnight, but not from losing the air in the system. The solid feeling comes from having stretched your lines and the already tiny freeplay made up of the 1 mm or less movement of the caliper piston seals against the rotors, resulting in, among other things, brake drag the next time you ride.

The fact of the matter is that once the piston in the master cylinder pushes past the fluid return hole (from the reservoir), no air or fluid can escape the now-pressurised line. If air can escape past the piston seals, so can fluid. The only time air or fluid can escape to the reservoir is when the brake lever is released (indeed, the design of an MC must allow this, so that fluid expanded by heat can return to the reservoir).


The only way to remove air in the system is by proper filling and bleeding technique. Binding the lever overnight will stretch out the lines and the seals giving you a false impression of rigidity in the system.

Take a look at drawing B in this diagram. It is of an axial MC, but the principle remains the same (diagram taken from: www.trialspartsusa.com/diagrams):

 

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That there is one of the greatest misconceptions about bleeding brake systems. You will get a rock solid lever in the morning from binding your lever overnight, but not from losing the air in the system. The solid feeling comes from having stretched your lines and the already tiny freeplay made up of the 1 mm or less movement of the caliper piston seals against the rotors, resulting in, among other things, brake drag the next time you ride.

The fact of the matter is that once the piston in the master cylinder pushes past the fluid return hole (from the reservoir), no air or fluid can escape the now-pressurised line. If air can escape past the piston seals, so can fluid. The only time air or fluid can escape to the reservoir is when the brake lever is released (indeed, the design of an MC must allow this, so that fluid expanded by heat can return to the reservoir).


The only way to remove air in the system is by proper filling and bleeding technique. Binding the lever overnight will stretch out the lines and the seals giving you a false impression of rigidity in the system.

Take a look at drawing B in this diagram. It is of an axial MC, but the principle remains the same (diagram taken from: www.trialspartsusa.com/diagrams):

You missed the part where I said, "...forcing small air bubbles into the fluid..." And then I said, "Then when you bleed again, they should come out with the fluid."

I don't disagree that you are stretching the lines a miniscule amount but as long as your discs are not warped, pad knockback shouldn't be an issue. What happens (even if you don't bleed again in the morning) is that since the (compressible) air is now in solution in the fluid, the lever feels alot harder. Once you heat up the fluid again, the air expands, escapes the fluid and becomes compressible again.

At least this is what I have gathered after chasing my tail with a bleeding problem a while back.
 

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Heres the easy way to bleed the system.

 
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