2012 with front brake problems

6 replies to this topic
  • luvnoldcars

Posted February 06, 2012 - 04:18 PM


i have a 2012 yz450f with 1.7 hours on it. i noticed that there was alot of brake dust on the caliper so i put it on the stand and spun the front wheel and it dont spin very good. when i spin it as hard a i can it only goes around one and a half times and you can hear the pads rubbing the whole time. i did notice that when you pull in on the brake lever the rotor moves about a 1/16 to an 1/8 of an inch towards the fixed pad.things i done so far is greased the caliper pins with auto caliper grease but didnt help. the next thing i did was put on a steel braided line on just in case the factory one was kinked but still didnt fix it. i dont have a clue what to do next. this bike was only ridin for .2 hours outside in dry grass then 1.5 hours on a indoor track. its BRAND NEW. also after you push on the caliper to spead the pads it spins great. help please

Edited by luvnoldcars, February 06, 2012 - 04:20 PM.

  • BBrown626

Posted February 06, 2012 - 06:57 PM


Perhaps your axle was not properly installed and shifted? Try loosening the pinch bolts, torquing the axle nut, aligning your forks and torquing the pinch bolts. Are you sure you don't have something stuck in the caliper?
Take the wheel off and see if the brake functions properly. Give it a couple pumps and then spread the pads apart.
Is the rotor bent or is the drag consistent all the way around?
Kind of hard to figure out without seeing it. Good luck and congrats on the new bike.

  • luvnoldcars

Posted February 06, 2012 - 07:36 PM


i checked the caliper and pumps out fine and pushes in fine. it also goes back in little bit when you let off the lever. tomorrow i will lossen up every thing and realign it to see if that helps.

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  • Stu2

Posted February 07, 2012 - 01:00 AM


Take the caliper off and grease the locating pins that it slides on, there are little rubber boots on them

  • beezer

Posted February 07, 2012 - 08:34 AM


Your disc is prolly bent.

  • grayracer513

Posted February 07, 2012 - 11:53 AM


It's normal for a disc brake to drag, and even more so for new pads to do it. First, you need to know that most of this drag is considered inconsequential, because at any speed at all, disc brakes require so much pad pressure to be effective that the fact that the pads touch the rotor doesn't have any real effect on overall drag on the bike.

Disc brakes drag because they have nothing whatever built into the system to return the pads in the way that drum brakes do. The reason they don't is because on the one hand, the caliper pistons are far larger than the master cylinder pistons, and if the pads had to actually move any distance, the lever travel that would be required would be impractically long, and once again, pulling the pads back away from the rotor isn't necessary.

Brand new brakes often drag just a little more than well used ones do because for one thing the pads haven't yet worn to perfectly match the rotor surface yet. If the caliper is just slightly out of square with the rotor, this is even more noticeable. It usually improves with a little mileage.

My advice is to confirm that the caliper will move on its pins with reasonable freedom (stiffly, but smoothly) and let it wear in a bit. I don't recommend using grease on the sliders because it gathers dirt.

  • briangriff321

Posted February 07, 2012 - 12:42 PM


When i get new pads i like to run around the track draging the front brakes to burn them in faster...usually a couple laps around the yard will work

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