How firm is your rear brake pedal?

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John R

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I've been dealing with rear brakes issues for awhile now. When I bought my '06 new, the rear brake pedal was pretty firm when I applied the brake. With 12,000 miles on the bike now, the pedal started getting softer and traveling farther when I apply the brakes. I put on new EBC HH pads and have bled the lines twice now. I took it to a Yamaha dealership and they said they had never seen a problem like that, but that they also seldom see a Vmax so their not sure how brake travel there should be. When I apply the rear break, the pedal travels maybe 3" down, but never really firms up. I can skid the rear tire, but I have to mash on it. So, how firm is your rear brake pedal and how far does it travel?
 
my "06" is the same way , its always been spongy & without using the front brake , it would take a long time to stop because of its weight & under sized rear brake ! Just another poor design !
 
That isn't normal. I wonder if the line is failing internally or if the master itself is wearing out. It may not be a bad thing if it's harder to lock up the rear brake anyway.

Sean
 
The rear brake is MORE than up to the task of stopping this bike. The rotor is HUGE compared to most.

My '06 has this same issue and I have braided line, bled system, Galfer rear rotor, and EBC HH pads. I need to check out the master as well as the caliper... Sometimes I get ZERO brakes from it... NOT GOOD!

Chris
 
I try not to use the rear brake, but it doesn't work well with a 600 lb bike. So I lowered my pedal purposely so that when I do use it, it takes a conscious effort. I am not used to using the back brake at all.

With that being said, I would say there is probably something wrong with the caliper affecting the braking effort/pedal travel. I'd inspect everything; pads, lines, caliper pistons; clean it all with brake cleaner; reassemble; and then bleed the system well.
 
w/out pressing on it, the rest position of the pedal is correct, right?
 
Is it me or is it odd that, so far, those who are having the same issue as me all have '06s? One2dmax, as I was leaving the Yamaha dealership, the service manager was scratching his head over the symptoms as I described them. He then said something about maybe a master cylinder issue. I asked him what the symptoms of a bad master cylinder would be and he basically described what I had been telling the yahoos all along. I'm going to take it to another dealership. I just don't have time and patience to work on my toys anymore.
 
Gamorg2, yes, when npt pressing on the brake pedal it is level. When the bike is not moving, the pedal is firm. As soon as the bike starts rolling, the pedal gets soft and travels farther.
 
How old is the fluid, is it orignal from factory?

Perhaps a fluid transfusion is in your future?
It may need new fluid and a good bleed. Moisture absorption.:confused2:
 
That isn't normal. I wonder if the line is failing internally or if the master itself is wearing out. It may not be a bad thing if it's harder to lock up the rear brake anyway.

Sean

+1. Definately NOT normal......My 95 is very firm........Brings the porker down in speed very well.........with alot of help front of course.........sounds like a problem that needs persuing..........If it's the master cylinder it's failing very prematurely for a bike that young......my .02.....
 
My '06 travels 3/4", the '99 travels 1", each has plenty of braking power. A slight bit more pressure and the rear tires will lock up on both.

Either bike will stop easily with only the rear brakes applied.

danny
 
3" of travel is NOT normal.....my 06 has about 3/4" at most, and will lock up the wheel easily. I would try swapping the fluid out first.
 
Gamorg2, yes, when npt pressing on the brake pedal it is level. When the bike is not moving, the pedal is firm. As soon as the bike starts rolling, the pedal gets soft and travels farther.
Make sure your break line is not on or near the exhaust, sounds like either the fluid is heating up too much or you have a bad master cylinder.
 
I had an issue with my rear brakes, Took forever and 2 days (and a mityvac) to get them bled out to where the pedal was solid again. Might be just air.
 
i was looking at my brake, b/c maybe its about 1 1/4" travel, and can you adjust that screw that presses on the cylinder?
 
My 2002 has the same issue. Travels real far. I bled it and changed pads. I have galfer rotors. Gonna try ss brake line. Maybe the rubber one is just expanding due to age
 
From Sean
I wonder if the line is failing internally or if the master itself is wearing out.

Holy Shit!!!..
Today, I was replacing my fuel sender unit.. (Hate that I have to damn near take the bike apart to get to the freakin thing).. With the back tire and shielding removed, I could see from the opposite side of the bike. Getting ready to re-assemble everything I noticed the Rear Brake Master Cylinder Reservoir (RBMCR), looked like someone poured acid over the cap. It was totally broken up and crumbling away. I could actually see the lip of the rubber diaphragm that should have been covered by the cap. Note: I was just in that area last week, doing some testing on the fuel sender, and from the outside of the bike, the reservoir cap looked fine.
I'm not 100 sure, if loosing pressure in the "RBMCR" would cause my brakes to go spongy, or fail completely, but I just ordered a full replacement set. I figure, if it's got a diaphragm in there, it must be there to build pressure. I forgot to take a picture, but I will post what it looked like, when the replacement get here. No riding for me till it does..:bang head:
 
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