Rear brake not performing

[thejsnide]

I recently dropped my 620 on its ride side... In doing so, the rear brake is now not performing as it should.  By that I mean, when I am going about 15mph and I stand on it, it doesn't stop me.  I usually don't use the rear brake unless I have to come to a really sudden stop.  What is causing this, is it the master cylinder that needs to be replaced, or something else.  The lever did bend in toward the bike.  Can someone enlighten me.

[printman]

Does it work while pushing it?

Or on a rear stand?

If not, the first thing I would try is to bleed the brakes. It may have developed an air bubble in the line from being dropped.

If it doesn't fix it, the master cylinder may be damaged.

[Slide Panda]

Ok, I was working on my post while printman posted - but looks like we both suggest bleeding as one ofthe 1st things to do

Well, rear brakes on the Monsters aren't the most powerful things going anyways.

When you say, it doesn't stop you - can you be more specific?  Like it does 0 to stop you, or just less than you expect?

Next question, how old is it?  And have you ever bled that brake?  While it's possible the drop did something - it might just have accentuated an existing condition.

If you've bled then fairly recently, the drop might have caused more free play.  You can adjust that, to an extent.  But if you've never bled your rear brake I might start there.   

[thejsnide]

No, I have never bled the brakes.  For example of the stopping power:  I was doing about10mph and stood (literally) on it, and it was baaaaarely responding.  I don't really use the rear brake at all, but I would still like to know it works if I needed to come to an abrupt stop.  The brakes are stock from a 2005 620 and to my knowledge probably have never been bled. 

Also, I am new to bikes, so what do I need to do to bleed the brakes...  Open the reservoirs?

[printman]

http://www.webbikeworld.com/Motorcycle-technical-articles/bleeding-motorcycle-brakes/bleeding-motorcycle-brakes.htm

I use a mity-vac, but have done it without any special tools also.

Without tools:

1. place something under resevoir, and have a wet towel ready in case you get brake fluid on the paint
2. find the nipple end on the caliper attatched to the banjo/brake line (that just sounds wrong  )
3. fill resevoir to full mark with new fluid - read manufacturers description
4. attach a clear hose at nipple that is snug, have zip tied a time or 2 to make sure air doesn't get back in.
5. apply pressure (steady pressure, not stand on pressure) to brake lever
6. open nipple with a open end wrench slowly allowing fluid to escape - the lever will drop
NOTE*** This sort of requires a feel to it to do it best so you may go thru more fluid than normal the first time.
7. Retighten snug not overtight the nipple BEFORE you release the lever
8. Repeat until brake lever feels firm and airbubbles are not seen coming out of hose.

WARNINGS*** Brake fluid is corrosive to paint, and other finished surfaces. I use a special can (small empty cans from lowes/HD) to drain into, then take it to the dump on hazmat days. Also be careful on the pressure applied to the lever, I have had it a time or 2 shoot fluid up out of the resevoir by being in a hurry. Find your pace that works. If you let up on the lever before it may cause air to get back in, making it take longer.

[monster monkey]

  I'm actually having the same problem, but found my lever bottoming out on my cat, which is weird. I'm going to try and adjust, then maybe take it to the shop since it's still under warranty. Maybe you should check for that also...

[thejsnide]

I rode the bike around the other day b/c I was in serious denial... I kept applying pressure to it while I was in my neighborhood, and it came back to life?  This could be good or bad as well... My speedo did the same thing as after I dropped it the needle got knocked up to 30 instead of 0... I just got on her a little and it dropped back to 0.  If it not broke, don't fix it...hopefully.  Thanks for the tips and help from everyone.