2000 YZ 426...rear brake issue/problem?

I recently flushed my brake fluid, standard maintenance practice. :bonk:The rear brake worked fine for two rides and there is no evidence of a leak anywhere in the rear brake system and the reservoir is full. I did notice that when we adjusted the height of the rear brake lever, the adjustment screw (if you call it that http://www.yamahaoftroy.com/fiche_section_detail.asp?section=36532&category=Motorcycles&make=YAMAHA&year=2000&fveh=963 , located in the package marked #2) was bent. We adjusted the rear brake lever and I noticed that the rear brake quit working all together. :excuseme: We adjusted it back, and it worked fine. Is it possible that the master cylinder is bypassing perhaps?:bonk: I am thinking that I need to buy the new guts (as indicated above in the link) and rebuild my master cylinder...has anyone ever had an issue like this before? Thanks.:smirk:

I recently flushed my brake fluid, standard maintenance practice. :bonk:The rear brake worked fine for two rides and there is no evidence of a leak anywhere in the rear brake system and the reservoir is full. I did notice that when we adjusted the height of the rear brake lever, the adjustment screw (if you call it that http://www.yamahaoftroy.com/fiche_section_detail.asp?section=36532&category=Motorcycles&make=YAMAHA&year=2000&fveh=963 , located in the package marked #2) was bent. We adjusted the rear brake lever and I noticed that the rear brake quit working all together. :excuseme: We adjusted it back, and it worked fine. Is it possible that the master cylinder is bypassing perhaps?:bonk: I am thinking that I need to buy the new guts (as indicated above in the link) and rebuild my master cylinder...has anyone ever had an issue like this before? Thanks.:smirk:

Also, the rear brake caliper is working just fine. The brake pads are in great shape. i know this is a very simple system, but never had this issue before.

If the "screw" that fits in joint #6 is bent, get a master cylinder kit and rebuild the master cylinder. It's really cake to do, just keep things clean when you work on it and don't put the piston seal back in "dry".

If the "screw" that fits in joint #6 is bent, get a master cylinder kit and rebuild the master cylinder. It's really cake to do, just keep things clean when you work on it and don't put the piston seal back in "dry".

Appreciate it. I had a feeling that is what i needed to do, I just wanted to make sure.

So, we figured out the problem with my rear brake. Inside the master cylinder, there was a small build-up of sand from the dunes. Don't know how it got in there, but it had kept the internal valve from moving the necessary distance to port the fluid through the master cylinder.

My buddy thought he would help me out by flushing my entire system after fixing this issue. It was nice of him, except for the fact when he bled the system, he did not prevent any fluid from soaking the brake pads. It has always been my understanding that when brake fluid gets on brake pads for a car/truck, it ruins the pads. Does this work the same for my m/c pads? i am assuming it does apply here as well. What do you think?

Check out the rectangular reservoir. The one on my 2000 426 got distorted by heat from the pipe, and dirt can get in that way. I replaced it with a new one, and wrapped self-adhesive foil tape around it to deflect the heat.

Check out the rectangular reservoir. The one on my 2000 426 got distorted by heat from the pipe, and dirt can get in that way. I replaced it with a new one, and wrapped self-adhesive foil tape around it to deflect the heat.

Thanks for that, I will check it out.

You can "try" to clean the pads with a product like Brakleen. Then again, pads are a safety device and it may be "cheaper" to replace them than find out they didn't clean up as well as you thought.

In my experience with cars - never had that happen on a bike, but theyr'e basically the same stuff - the pad can be cleaned to the point that it will work, but they crystalize quickly. Not sure if dirtbike pads get hot enough to do that.

You can "try" to clean the pads with a product like Brakleen....

Replace them. Rocky Mountain has their own brand that are cheap, and work well.

Good luck!:banghead:

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