got a brand new 04-05 R1 brembo master cylinder... trying to use it for my handbrake...bled it right side up and it works fine, as soon as i flip it upside down it goes spongy.... i bled it for two hours from the master cyclinder and the caliper.. still spongy, but then i flip back to right side up and rock hard...

anybody know anything about this or know what's going on..?

az
sf

 

gotta be some trapped air somewhere,are you vacuum bleeding it?

 

Just what I was about to ask...

 

which kind is it does it have the little plastic resivior or does it have the resivior as part of the lever all metal if it is the one piece all metal resivior u cant turn them upside down






ps are u guys gonna be in tulsa on fri night this weekend like last year cant wait is gonna be badass

 

Ive installed the same master for a friend with no problems, I actually really like that master.....Plain and simple you havent bleed it good enough, either keep trying or have someone better at bleedin do it for you....Theres no way you should be spending 2 hours bleedin it, 1/2 hour tops if your good at bleedin..And Ive never used a vaccumm, its not needed at all

 

but why is it rock hard when its right side up, but the second i turn it over, it goes spongy...?
i used a vacum pump too...

 

id try bleeding it upside down..see if that helps

 

never mind i'm an idiot now i see u said an R1 brembo mc i am dumb

 

Because the air bubble probably goes to the res when you have it right side up, but when you flip it the bubble moves into the lines again......You must get that air out then it will be rock hard whatever way its mounted...

 

its like the second one.. and i bled it forever while it was upside down....

 

He said its from an 04-05 R1, those are remote res style....Hes got the right master just needs to bleed it properly

 

and while its upside down, the streams that come out of the caliper and cylinder are solid..... no air...

 

Where are you bleeding it from? the air can get stuck in many places, especially at the banjos......

 

yea i didnt see that u said R1 mc thats what a buddy of mine has and we had no trouble bleeding it and it works great i know thats not what u wanna hear if u dont get it by this weekend i have a brake guy that bleeds all of our stuff and they all work great just let me know

 

handbrakes are weird..some can bleed in 30 seconds where others take hours..

 

Have you bleed the master at the masters bleeder? And have you put the diphram back into the res with the cap on?

 

im bleeding it from the actual master cylinder, than i bleed it from the rear caliper..... i guess ill try again and just keep bleeding and bleeding and see if i can get it to harden up... i just started to think that something mechanically wouldn't allow the master cylinder to be used upside down....

thanks for the input guys,
appreciate it...
sf

 

Naw man once all the air is out they work pretty much in any position.....You might want to go for a ride and use it a little and get the bike shaken up then go back to bleeding, Ive done that in the past to help loosen up any stuck air bubbles.....

Like mentioned sometimes their a *****

 

real simple, keep the resi above the damn mastercyclinder which means Relocating it, hold the master above the bike in mid air and have some one hold the resivour while u turn the master cyllinder each direction pumping it furisouly till all air bubbles flow out into the resi, make sure to have the cap off while u do this. bleed it at the banjo bolt to when u mount it to the clip-on squeeze that damn lever n crack the banjo bolt and so on.. don't be afraid to bleed it.

 

aight... ill give that a try too.... i've been using handbrakes for 2 years now and never had any problems bleeding them except for the 954s,929s and now these... they both do the same thing.... but ill give the suggestions a valiant effort and see where i land...

thanks again homies,
sf