Rear brake kaput

3 replies to this topic
  • chrisn6104

Posted May 14, 2006 - 05:41 PM


I'm assuming it's probably the master cylinder. Just want to try and make sure before I buy a rebuild kit.
It worked fine last time I used it. I tried to close the caliper after replacing the wheel and nothing. Fluid lvl is good, I tried bleeding it and it just oozes out. The piston barely moves when I pump the brake lever sometimes even moving back in. When it finally closes up on the rotor there is no presure. When I open the bleed valve on the caliper and push the piston back fluid squirts out like it should.
Not sure how to test which one is bad but a master cylinder kit is far cheaper then a caliper.
Sound like the master cylinder is just worn out?

  • XriderR00

Posted May 16, 2006 - 10:57 AM


I'm having a similar problem only where the piston isn't coming even close to the rotor. :ride:

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • chrisn6104

Posted May 16, 2006 - 12:43 PM


Well I went ahead and ordered the parts for the master cylinder. I pulled it apart cleaned it out tried to bleed it again and still nothing (wont even make pressure when I plug it with my finger). We'll see if the new parts fix it or not. I'm thinking if it was the caliper the seals would be leaking fluid .... could be wrong though :ride:
Guess if this doesn't work I'll replace the seals in the caliper.

  • XriderR00

Posted May 16, 2006 - 02:44 PM


I know that mine wasn't the master cylinder, because neither the 450 one that I have nor the 400 one worked with the same caliper (my bike is converted)

Related Content


The "going back to the other darkside" adventure... by Monk

Dirt Bike   Make / Model Specific   KTM   250/350/450/505 SX-F & XC-F (4-Strokes)
  • Hot  113 replies

Yamaha YZ450F 2017 by Chris.GVS

Yamaha YZ450F 2017
  • * * * * *
  • 1 review
  • Last review by Tommyk_55
  • On January 15, 2017

BIGBORE FOR YZ450F 2006? by Taattie94

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies

Megabomb Fitment by 288yz450

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply

Wilson the Blue Privateer by jetfuel

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  50 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.