Insane J

Okay this is the problem:

Whenever I use my footbrake, things are all good... Footbrake is like 100% solid all the time But after using my footbrake, and reach out for the HB (brembo 16x18 in combination with Fullthrottle) I have to pump that sucka up one time before it's 100% solid... The HB is a bit softer when I get it the first time, after that, it's solid...

I always thought it was a problem of air somewhere in the system, but Hey, Guess what I found out... It's not

I always had this problem, since the first day I installed all the sh*t... First I was rocking a different master, and also had the problem, I bleeded the system like many many times... Always at the local Motorshop, with a vaccuum pump bleeder. Was easy as hell, only took a couple of min's.

But I always thought there was still a tiny bit air left cause I always had to pump the HB up one time... Well, I had enough of it today so I decided to bleed the system manually... I bled it at the HB master, and at the rear caliper, the only thing that came out of the system was solid braking fluid. Not even one tiny air bubble.

I wanted to crack all the banjo's also, but then I saw something... My footpedal was moving when I pulled the HB. That cought my attention, and me and my father (how cute, I know ) had a look at it...

This is what we found out:

Whenever I use the footbrake and reach for the HB, the footbrake is in normal position... Well DUH, but listen up. When I pull my HB the first time, I said it was a bit soft didn't I ?

That's true, and it's not caused by air in the system, it's caused by a crappy footpedal or something. Cause when I pull the HB for the first time, I can see the footbrake pedal coming up a little bit

And after that, the foot pedal stays at that position, and my HB is solid as a rock...

So my HB is soft the first time, cause first, it pushes the footpedal a little bit up, and only after that it starts to build up pressure... This happens every time I use the Hb after the footbrake. It's just a tiny little bit that the footpedal comes up, not even a mm I think, but if you have a good look at it, you can see it...

Okay, now another question;

has anyone ever had the same problem ?? I think especially with a bit older bikes ? Cause I have a F2, and the whole footbrake system is more crappy then maybe a recent F4i more used offcourse, older technique etc.

E-Dub, maybe you with the F3 ?

Tell me guys, has anyone ever experianced the same problem, and maybe didn't knew what it was ? Or maybe did knew what it was and fixxed it ? Cause I don't really know what to do about it...

Ok, a long thread, I hope to see alot of reactions here, come one post ******

rinxi

right... sori i'm gonna be of no help

Trachito

hmm, i had a slightly different problem and i don't really know why it happened.

my problem was when i'd ride for quite a while, my foot brake would start to get spungy and eventually useless. i'd be going 60 mph and have to rely strictly on the front brakes and downshifting because the foot brake petal would literally push all the way down without ANY resistance. it was as if i had no fluid in the system. if i'd let the rear brakes rest for a while they'd go back to working fine. i found out that i was riding the footbrake without noticing. i consciously stopped riding it and it works perfectly fine.

i dont know why it stops working all together when i accidently ride them though. u'd figure that all that would happen is ur rear brakes would wear down super fast but no, the suckers just stopped working briefly. anybody got an idea why?

Insane J

I know it, you're braking fluid gets to hot, and then get's spungy like hell ! Just put new (better) braking fluid in the system, and then it will hold up longer before it gets spungy and doesn't work anymore...

But anyone tip&ideas for my problem ? Or anyone heard of this before ?

MikeM

you said the first time you pump the hb, the footbrake pedal moves up? What if yopu put a stiffer return spring on the foot pedal, so it would already be all teh way up//

Insane J

no, I don't think that wouldn't matter... cause it almost doesn't move much up... so little, and only if you use the HB = Much pressure on the foot pedal... so I don't think that would matter

LivingCanvas

I have the same problem and i ride a 02 f4i.

NME

I ve seen that happen on some bikes. it actually started working fine in time.

Catman

you think maybee the banjo has to move the fluid in it first and thus pushes a little fluid back the other way for a split second

crtchrktrcr

^ this guy is correct..

insane, this is kind of common sense, fluid is being pushed back n forth, like if you hold pressure on the hb, then hit your fb, it moves the hb out. and when you hold the fb, and grab the hb, u can feel it.. just adjust the height on your foot pedal, and make sure you tighten the nut down on it.. so it doesn't move up anymore, and u'll be fine, or just **** it up

f4stunna

or theres still air in your line..... just becuase you bleed it at the caliper and no air comes out doesnt mean there isnt air in the line. bubbles can become trapped in spaces and are very hard to get out.

BIG-D

J I think it is exactly what youre saying, I have had this problem also

f4stunna

everyone has, its the nature of having 2 masters working with eachother. but thats not whats causing it to be mushy.

cool_jocke

+1

mikkee

This is true - it is suppose to do that... There's nothing wrong with your system.. When switching from foot to hand or hand to foot u should be a bit forward in the BP when switching.... I't only takes split second to switch and shouldn't be much of a problem... It's all timing.. just practice it a bit.

cool_jocke

im using brembo 16*18 and its really the best setup but it really needs one pump to get it stiff, i tried 1000rr -05 radial and it doesnt need a pump, how strang is that......

moorport

I got the same problem on my f4i and my crf450, my solution, dual caliper! Then I won't have to worry about that footpedal feedback in my handbrake anymore.

solidjohnny

i have the same issue, but its not really a problem.... Like what F4stunna said, its how the system works. That one mm of movement in the foot lever is HUGE in terms of play in a braking system. Get a stiffer spring and it might get rid of that "mushy" feeling. Then all you have to worry about is the HB taking up the "slack" of the footlever when you switch from FB to HB. You'll get used to it.

Anytime you use your brakes, it will build up heat. All brake fluids, even racing fluid, will boil once it reaches a certain temperature. At freeway speeds your brakes will get extremely hot very quickly....like glowing bright orange and shooting out sparks!! When it boils air bubbles are created and you get no braking power....its just as if you didn't bleed your brakes properly. When you let the brakes cool down the air bubbles will eventually go away.

Old brake fluid can collect moisture which will lower the boiling point. Brake fluid that has been boiled repeatedly will fade faster and faster too. Guys that road race change their brake fluid before every race. So if you're on the brakes hard all day its a good idea to change your brake fluid often.....even more often than your engine oil.

Insane J

about a couple reactions above, I know it's not air in the system, cause I can see my FB pedal move up a bit when i reach for the HB...

Okay, so I hear alot of you guys have it... but you shouldn't have the problem if the footbrake pedal wasn't able to move around so much...

I watched the braking pedals of a whole load of gsxr's in the motorshop today, and they are mounted on a really solid way... So they can't move around unnecesserry... like up down, and sidewayz without doing anything ( I don't know the english word for that)

I think if you can solve that, so you're braking pedal can't move around without braking, the problem would be solved...

I allready try'd to adjust the height of my footbrake pedal, but that didn't helped... The problem was exactly the same when my footpedal was in the most highest position...

f4stunna

your mis-understanding. there are 2 issues here and you think its one. yes the pedal moves around. but thats not what is causing your lack of pressure in the line. the pedel/lever will move like that becuase there are 2 master cylnders pushing against eachother. no matter what you do, it will still be like that.

now, as for your problem with it being soft until you pump it. that is air in the line. now, its probubly before your foot master, in the line somewhere. and becuase thats where it is, the foot pedal will still work fine.

DONT WORRY about your foot pedal moving. IT IS NOT AN PROBLEM.....