front brakes locking up

[SSpeeDEMONSS]

i had my bike('00 yz426) at my friends house today cleaning up some the plastics and making a whip mount for it. i rode it around a little. i rode it for maybe 30 minutes then set it in the garage for maybe 20-30 minutes. then i went to ride it again and after riding around the block a few times i found that the front brakes were wanting to lock up. so i took it back to his house and i could barely push it. if i pulled it backwards the front tire would just stay locked up. so i looked over the brakes a little and after finding nothing wrong with anything(that my friends or i could find) we just let it sit. after a while, like after it cooled a little(5-10min) it would roll again. so i rode it up the street and by the time i was on my way back the brake was already dragging. this was without using the front brake at all. so, here i sit wondering what it could be.

i was at the honda dealer picking up a friends tire so i asked one of the guys what it could be. he said it could either be; 1. water in the lines 2. master cylinder is clogged 3. master cylinder needs to be rebuilt 4. caliper needs to be rebuilt or 5. return spring on the caliper was worn. so i go back and check the master cylinder seemed to be ok(not clogged). then i pulled the caliper off and there was no return spring so i dont know what else it could be. any help would be greatly appreciated. thank you and sorry for the long post. ?

[stroker101]

has anyone adjusted the front brake lever recently?

if so it is adjusted way too tight/sensitive. a small amount of play should be present between the brake lever and master cylinder plunger. that way the hot fluid has room to expand. let us know what you find. ?

[BlueMan78]

I had this happen to my 426 and I just replaced the plunger and o'rings in the master cylinder. I also then routed my brake line CR style.

[JYD]

your front rotor is warped.

[SSpeeDEMONSS]

ok, i just got back from azusa canyon. i didnt really use my front brakes at all but i also didnt have any problem with the front brakes locking up whatsoever. we messed with the lever the other day and loosened it up but i guess i will have to ride it and use the front brake to be able to tell if it is still messed up. thanks for the help.

also, what is the cr style of routing the brake line? ive heard of that before but dont know what it is.

[RJB]

Shorter path from the master to the caliper. Do a search for more info, as there are some useful tips to stop it getting caught and ripped of your bike (if you aren't careful)

[John_Lorenz]

I had the same issue just recently

I found the problem to be the adjustment at the lever, was way to tight. when the fluid was hot it expanded and locked the front end. I later adjusted it down for more free play and all is well.

I also re-bleed the break just because....

[Satch0922]

John is correct. This has happened to me as well.

If it is a continuous drag or lock up then it's not a bent rotor.

[JYD]

If its a continuous drag or lock up then it's not a bent rotor.

this is not necessarily true.

[John_Lorenz]

If its a continuous drag or lock up then it's not a bent rotor.

this is not necessarily true.

Well it does matter just how bent or warped it is. the 2000 does not have a floater, it is locked hard so a warped roter will cause drag a really bad roter will lock

[Satch0922]

Thanks John. I did not realize the 2000 did not have a floater. ?

[oldnbold]

Strange but true sidenote here. I read a while back about how brake fluid is a humectant fluid meaning it absorbs moisture. Often brake fade is due to the amount of moisture in the fluid and when the fluid gets over 212F the moisture boils causing a mushy feel. But I digress.

Recently after all this rain, I noticed my trailer's master cylinder was weeping brake fluid from the screw on fill hole.Previously it was filled to the brim and now it was overflowing and squeezing out the top. The only answer I had is the fluid had absorbed moisture and expanded the volume in the system. ? I dunno.

[JYD]

Thanks John. I did not realize the 2000 did not have a floater. ?

[stroker101]

I had the same issue just recently

I found the problem to be the adjustment at the lever, was way to tight. when the fluid was hot it expanded and locked the front end. I later adjusted it down for more free play and all is well.

I also re-bleed the break just because....

hmmmmm?

[krotchwaffle]

i think my rear brake is dragging on my 00 426, but to look at the fluid level in the rear reservoir, it's half way between the high and low level lines. the pedal probably moves about a half an inch before it gets tight, so i'm not sure if it needs adjustment. i may take a look at it tonight. i thought nothing of it when i pushed the bike since i figured it was just a heavier bike, so it would be harder to push than say a 125. but, every bike i've ever pushed is easier than mine. i also have an o-ring chain, but i'm not sure how much of a difference that actually makes. i'm probably switching back to a standard roller chain and hope that helps a little. all my friends tell me that having the o-ring chain is like riding with your rear brake dragging.

[Satch0922]

Thanks John. I did not realize the 2000 did not have a floater. ?

Once again Jesse shows his style.

[John_Lorenz]

i think my rear brake is dragging on my 00 426, but to look at the fluid level in the rear reservoir, it's half way between the high and low level lines. the pedal probably moves about a half an inch before it gets tight, so i'm not sure if it needs adjustment. i may take a look at it tonight. i thought nothing of it when i pushed the bike since i figured it was just a heavier bike, so it would be harder to push than say a 125. but, every bike i've ever pushed is easier than mine. i also have an o-ring chain, but i'm not sure how much of a difference that actually makes. i'm probably switching back to a standard roller chain and hope that helps a little. all my friends tell me that having the o-ring chain is like riding with your rear brake dragging.

One of the things I have noticed on My 2000 is how much dirt, and debri get caught up in the calipers and the pads. I take mine apart from time to time and just clean them up grease the pins and make sure everything is free to move.

Might just want to do this, you will be surpirsed how caked up the dirt can be in there.

Satch

Apperantly you two have encountered each other ?