Help with Brakes Please!


4 replies to this topic
  • 5point9

Posted October 06, 2013 - 01:22 PM

#1

2000 yz426. The front brake was ok, but not real strong. So I removed the caliper, inspected the pads (which ended up being ok), cleaned everything and put it back together. At that point, I thought maybe I should just bleed them. As soon as I did my usual bleed job (squeeze, open valve, close valve, release lever) I immediately lost a lot of pressure. I had nothing for quite a while, but eventually got some braking, but very little.

 

I cant seem to get the pressure back up, even to where it used to be. I am almost through one bottle. I seem to have gotten most of the air bubbles out of the master cylinder. I tried bleeding through the banjo bolts as well, nothing. It just seems like the fluid does not "burst" out when pressure is applied. Just dribbles. 

 

Again, the brakes were ok before, not great. Now I've got nothing just from cracking the valve open once!

 

Help!



  • ekulb14

Posted October 06, 2013 - 06:33 PM

#2

try reveerse bleeding. Get a syringe and push the fliud up from the valve. sounds like you got air in there somewhere.  


Edited by ekulb14, October 06, 2013 - 06:34 PM.


Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • 5point9

Posted October 07, 2013 - 02:07 AM

#3

ok will do.

 

if it's a master cylinder problem, i would just find it hard to believe that it convienently started when I went to bleed the system! argh!



  • stroker101

Posted October 07, 2013 - 10:25 AM

#4

u can try removing the brake caliper, remove the master cylinder cap,...then pry the pads apart, forcing the piston back into the caliper. this may force any trapped air back up and through the M.C. u may have to pump the system up a few times and repeat. don't use the banjo bolt as a bleed off point.

once u get that firmer feeling at the lever, do a final bleed off at the bleeder valve on the caliper. use very small openings there, just enuff to allow fluid to pass and without the lever to blow through it's action.

 

(be sure to place something in between the pads so not to force the piston out of the caliper when applying the brake)


Edited by stroker101, October 07, 2013 - 10:31 AM.


  • Rkumle09yz450f

Posted October 11, 2013 - 10:09 AM

#5

I had the same problem I found that if I take the lever off and put a 7 mm deep well socket on the pin and push in and out slow and hold it for a few seconds works takes like 10-15 from line being empty but the cause was the lever did not allow the pin to full release inside the master so it would not let the air come back up threw and after I did that I could crack the bleeder and keep adding break fluid as it would go down the line an fill up the caliper and out the bleeder then bleed it like normal and worked fine,





Related Content

Reviews

Yamaha YZ450F 2017 by Chris.GVS


Yamaha YZ450F 2017
  • - - - - -
  • 0 reviews
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
Forums
Photo

100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies
Forums
Photo

Snake pit oct 30th by The Anvil


Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies
Forums
Photo

Megabomb Fitment by 288yz450


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

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.