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2018 YZ-250F REAR BRAKE?


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New 2018 with aprx 15hours. From time of new the rear brake has too much drag, squeals and gets super hot. I have taken the caliper apart, greased floating pins, bled system with fresh fluids etc. With the bike on stand, the wheel barely spins one revolution with considerable force. If I push the caliper over by hand releasing pad pressure the wheels spins 2-3x like it should. It seems like alignment or caliper needs shims or something ?? Any thoughts or anybody have this problem?    

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1 hour ago, Vintage Not Pimpage said:

Noticed today my FX had a lot of drag on the pads and they had been wearing a lot faster than my previous YZF. Pulled the head shields off and no more drag. 

Taking the heat shields off did not really fix your problem. they are there for a reason. 

If your hard on the brakes you will now be overheating the whole caliper. I've seen it where the caliper gets so hot that the left side will start pushing outwards unevenly. 

If you don't believe me I can send a pic of a old caliper

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New 2018 with aprx 15hours. From time of new the rear brake has too much drag, squeals and gets super hot. I have taken the caliper apart, greased floating pins, bled system with fresh fluids etc. With the bike on stand, the wheel barely spins one revolution with considerable force. If I push the caliper over by hand releasing pad pressure the wheels spins 2-3x like it should. It seems like alignment or caliper needs shims or something ?? Any thoughts or anybody have this problem?    

Check your brake fluid level in the rear master cylinder. If there's too much fluid the brakes can drag. Won't release right.
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9 hours ago, yz250f 78 said:

Taking the heat shields off did not really fix your problem. they are there for a reason. 

If your hard on the brakes you will now be overheating the whole caliper. I've seen it where the caliper gets so hot that the left side will start pushing outwards unevenly. 

If you don't believe me I can send a pic of a old caliper

 Never had an issue in 15 years of riding and racing yamahas. The replacement pads I use don't have heat shields either. 

Post up the pic I'm interested to see. 

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Went thru re-checked alignment for bind. not that. Going pull some fluid out and see but did bled the damn thing 3x. The caliper gets so crazy hot.. afraid of vapor lock or burn oil or brake failure. Going to maybe check aftermarket pads which I never do always use oem pads but not sure.  Will look into heat shield removal also.  Dealer has no idea whats up with it either. 

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10 minutes ago, metalmachinery said:

what do mean by free play at pedal/master?? Are you referring to pedal adjustment to foot free play? 

Rear brake has two settings, pedal height and free play. Ideally, during setup,, the master is disconnected form the pedal. The rider sits and stands on the supported bike. The boot to pedal relationship is approximated and the pedal position is established. Then the master is reconnected to the pedal. The pin should be able to slip right in and the master clevis easily wiggle up and down with no tension (or pressure) on it.. Any subsequent pedal position change, you must ensure the free play remains. If.. you remove the free play, the masters piston can cover the bleed hole in the reservoir. This will cause break application/lockup to occur due to hot fluid and followed by a failure of the brake to self adjust.

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