Front brake problems

[jmutiger]

Hi again..

I've been having the strangest problem with my front brake.. I'll start from the beginning.

First off, I rebuilt the bike this winter, and thus had the front wheel off the bike. The front brake inadvertantly got pulled until the pads were locked together.. Once I put the bike back together, I tried prying the caliper open, but wasn't able to. I had to crack the bleed valve, and then force them back. Okay, I get the wheel on, and ride the bike.. it's okay, the brake works fine.. But then I do a wheelie, and notice my wheel instantly stop spinning.. Okay.. I hit a wet patch of pavement and it locks right up on it nearly killing me.. Okay.. So I crack the bleed valve on the road, and ride home.. Once home I open the reservoir, and inspect the level (I have no sight window to check fluid level on my 1993 KDX250. ) Anyways, the level was about 3/4 of the way up, and I supposed it's possible that there was some fluid expansion, and the fluid had no where to go.. So I took 2 full "bleed" pumps out of the system (to the bar at the lever, ejecting fluid out of the bleed valve).. I ride it around, and everything seems good.. Until I went out today for a trail ride.. After doing a long decent, my brake lever was getting firmer and firmer, then finally the front wheel was locking up again.. Crack the bleeder, and take 2 more pumps out of it..

What part do I need to rebuild to get this problem to stop? I'm guessing it's in the master cylinder, but I'm not sure..

Also.. Do Honda CR pads fit on a KDX250? They both use Nissin's right?

Jon!

 

[flyinfish]

Same thing happened to me. In my case I had the adjustment screw on the brake lever turned too far in and it didn't allow for the fluid to return to the master cylinder after things heated up. I was trying to make up for a mushy brake by turning that screw way in. Hope this helps

Fish

 

[David Trustrum]

Bingo. Also happens with some aftermarket incorrect fitment levers. End result is the return hole in the master cylinder is blocked (perhaps with a bit of heat to seal the seals that wee bit more).

Check lever freeplay & or clean the hole out or maybe a MC rebuild is on the cards.

 

[jmutiger]

Thanks guys, this was the issue..

I replaced the lever over the winter, and I must of had a brain fart while installing the adjustment screw and lock nut.. I had the lock nut on the wrong side of the lever, basically it was hitting the master cylinder..

So you were both right, in a round about way.. Thanks!

Jon!