Yet, another rear brake problem :(

[ide508]

Hi all,

It's been two weeks that (I thought) my rear brake problem was fixed, done 400 km without sh*t, but today I took a trip down the Belgium Ardennes and on my way back... sh*t came back.

I suddenly realised that the exhaust'sound was abnormally high and noticed that every time I let the throttle go or use the clutch the bike respond as if some brake was applied. Not running freely at all !

Soon I found out that it should be the rear brakes pads that were "sticking to the disc.
I was on a small 2 way forest road where I could not stop, so I drove maybe 5km with that malfunction. Trying from time to time to unblock it by using the rear brake pedal.

After a while, it did unlock but when I stopped i see that the rear disk, pads,
pads'holder had been very hot due to the colour of it insde every single hole of the disc that "red' colour appears also.

This time, next week I'll have a trip to my dealer for sure, but before I would like to ask you if something like that has happened to somebody, and what in hell could have created it

Today's trip was all tarmac, and after the pads did unblock from the disc, I could apply full rear brake pedal with ... almost no brakes! Pedal hitting the G-it engine guard...
Back to square one

Unstoppable hey, until the brakes stop you

Thanks for you're replies

 

[Dave Ett]

Could it be you were riding with your foot on the brake pedal accidentally?

 

[ide508]

No no, the bike behave really as if the pads were glued to the disc. The engine was working quite hard, the exhaust noise sounded abnormally high and when I release the clutch the bike was acting as if brakes was applied.

After pressing a few time the pedal it got unstuck ...

I am bound to the dealer tomorrow. I fear that the master cylinder is the culprit. Let's see what they say about it, hope the disc is not burned / dead!

Will get back as soon as I know more

 

[Micky]

Some people set the brake pedal height by adjusting the small rod between the back of the lever and the rear brake master cylinder

This is a big NO NO .... it causes the pads to bind, there must be free play between the actuating rod and the master cylinder

Sue's rear pads on her 650 (almost identical to the 800, same set up) almost set the bike on fire in Kazakhstan because of a seizing master cylinder failing to return to the 'off' position ... with reference to your previous postings Bernard, and photo's of your rear brake with all the shit and crap on them then your master cylinder could be doing the same



C'mon Skywalker .... back on the case

 

[ide508]

Some people set the brake pedal height by adjusting the small rod between the back of the lever and the rear brake master cylinder
This is a big NO NO .... it causes the pads to bind, there must be free play between the actuating rod and the master cylinder

Haven't touch it since new !

Sue's rear pads on her 650 (almost identical to the 800, same set up) almost set the bike on fire in Kazakhstan because of a seizing master cylinder failing to return to the 'off' position ... with reference to your previous postings Bernard, and photo's of your rear brake with all the shit and crap on them then your master cylinder could be doing the same

I think that it is the case, but without the reference of my previous post

C'mon Skywalker .... back on the case

 

[skywalker]

Oh go on then Micky.
From the pics of this now salt free infested bike I deduce the following.
1 given the heat colours on the disc its overheated !- No Shit!!
2 the rear caliper's not as clean as we were intially lead to believe ! see intial thread. a comprehensive investigation would be a good starting point. Is the piston sticking, does the caliper slide freely on the pins, is there corrosion behind the steel shim that the pads fit to on the caliper, not the pin that holds 'em in I hasten to add but on the other end

3 Micky's answer - there's no free play between the actuating rod and mastercylinder
4 Due the"sandy/salty" environment it originally lived in prior to its miraculous transformation into squeaky clean component the master cylinder piston is sticking in its housing
5 Really can't be arsed as according to our poster I am the devil's spawn!!

 

[cristhemuso]

Probably not relevant but your spindle looks completely different to mine on LHS. I dont have a hex socket like you have on yours. My bike is Apr 2009.
Just interesting.

 

[ILMV]

+1 Chris, looks like the spindle from the front wheel :-/

 

[Micky]

Mines a 2008 and the spindle is integral with the alloy block, so undoing the 24mm nut on t'other side the spindle doesn't/can't spin round.

I think later models the spindle is loose in relation to the alloy block and so you will need the hexagon to be in a position to stop it turning while you undo the 24mm nut!

 

[v8legend]

Now I'm really confused. Mine is one piece, but looks just like the picture?

 

[Micky]

Now I'm really confused. Mine is one piece, but looks just like the picture?

Was only a suggestion

 

[smaytum]

Two thoughts...

1) have you had the rear wheel off recently? If you put the spacers in the wrong way (the left on the right side and vis-a-vis) then it pushes the disk onto one of the pads!

2) more of a long shot... Check the wheel bearings are good. My rear bearings went and the wheel again shifted onto the pads. Before the bearings showed any signs of wear, the brake pads were wearing fast.

Rgrds
Steve

 

[ide508]

Went to the dealer yesterday, they did change the brake fluid...
So far so good, but haven't ride much yet.

According to the "expert" no need to change the pads yet and the disc are OK.

Cheers

 

[petera]

Some people set the brake pedal height by adjusting the small rod between the back of the lever and the rear brake master cylinder

This is a big NO NO .... it causes the pads to bind, there must be free play between the actuating rod and the master cylinder




C'mon Skywalker .... back on the case

OOPS guilty I'm afraid. The pedal seemed too high so I adjusted it to get more movement before activating the rear brake. Anyone give me a quick guide on how to re-set it correctly

Thanks
Peter