Had to replace the 33" hose for a longer one. Ive been bleeding this brake with the vacuum pump. And now it does not have any pressure. I dont know if im missing one of the steps in bleeding brakes. But there is no pressure coming onto the lever or pads for stopping. Any suggestions guys?
agk hydraulic brake
- Thread starter deonsrace
- Start date
Venice Motor Bikes
Custom Builder / Dealer/Los Angeles
I had a similar problem bleeding mine... Don't use a vacuum bleeder... Place the caliper HIGHER than the lever (so the bubbles go up) & bleed out all the air by repeatedly squeezing the lever (& re-filling). 
23tiny
New Member
or you can put a long hose from the caliper or bleeder screw and submerge it in a little bit of brake fluid. Make sure the master is always full, pump up the brake 10 times and hold the pressure and then open the bleeder screw releasing the bubbles. Continue this process until you get good brake pressure.
Hope this helps.
Hope this helps.
I've never had good luck with a vacuum bleeder. Getting the caliper higher than the master cylinder, like Venice suggested is easy on a bike system. Not so easy on a car.
I'd block the pads so they don't push out too far. Use something as thick or a little thicker than the rotor. (this might be redundant on your caliper. I'm not familiar with the design).
Tom
I'd block the pads so they don't push out too far. Use something as thick or a little thicker than the rotor. (this might be redundant on your caliper. I'm not familiar with the design).
Tom
Venice Motor Bikes
Custom Builder / Dealer/Los Angeles
The problem is that air bubbles get trapped in the brake lever (& in the caliper) & don't get pushed out when bleeding. 
Thats why holding the calper higher (so the bubbles rise) works.
Thats why holding the calper higher (so the bubbles rise) works.
Davezilla
New Member
I don't use vacuum bleeders either... most the time they just won't work..
What I've done before that works great is to run some aquarium tubing from the bleeder valve up to the master cylinder and submerge that end in the fluid, then pump the lever until all bubbles are gone, if you go too fast tho it'll whip up little tiny air bubbles and send them back into the system.
Another trick that works on really stubborn systems is to reverse bleed them by hanging a bottle of fluid above the master cylinder level and connecting a tube to the bleeder valve, then let gravity do the rest. This trick is very effective but it will overflow the master cylinder if left unattended, this is also a slower process but it works.
What I've done before that works great is to run some aquarium tubing from the bleeder valve up to the master cylinder and submerge that end in the fluid, then pump the lever until all bubbles are gone, if you go too fast tho it'll whip up little tiny air bubbles and send them back into the system.
Another trick that works on really stubborn systems is to reverse bleed them by hanging a bottle of fluid above the master cylinder level and connecting a tube to the bleeder valve, then let gravity do the rest. This trick is very effective but it will overflow the master cylinder if left unattended, this is also a slower process but it works.
Davezilla
New Member
I had a similar problem bleeding mine... Don't use a vacuum bleeder... Place the caliper HIGHER than the lever (so the bubbles go up) & bleed out all the air by repeatedly squeezing the lever (& re-filling).
I like this idea too, it's similar to the reverse bleed method I use on stubborn systems and I may need to use this method on one of my motorcycles since it's extremely tough to get all the air out of the rear caliper.
runnermike
Member
No, you should not have to mash the lever hard. If you have a LBS that deals with hydraulic brakes they more than likely will bleed it for you. Just a suggestion..
It took me about a good 20 mins of bleeding, filling, pumping lever, and repeat. But, the thing stops on a dime now!
It took me about a good 20 mins of bleeding, filling, pumping lever, and repeat. But, the thing stops on a dime now!
KCvale
Well-Known Member
This may sound silly but..
How are the disc pads?
Is the caliper aligned properly?
How about your brake lever pull adjustment?
Just other things to check after major brake work.
culvercityclassic
Well-Known Member
I have had issues with the stock pads in these brakes, switched to metallic and what a difference....
young grease monkey
New Member
you should do a yz85, it has a power valve unlike the yz80. this means better low end torque. or a 125 would be cool, but probably too much power for a bike frame. you will need some real strong wheels for just a yz 80 or 85
KCvale
Well-Known Member
Re: 2 stroke build. yz80 or KT100
It's a nice motorcycle frame, with pedals ;-}
You could try a MotoPed.
It's a nice motorcycle frame, with pedals ;-}