Rear brake overheated
- Thread starter pitrat101
- Start date
How do you know if the pins on the caliper are not seized due to lack of maintenance?
I believe the rear brake pedal can get stuck on a corroded pin and keep the brake applied
Have no idea why mine did.
The pedal was free, the lever did not engage with the master cylinder (that I could determine), yet after 10 miles or so, it was about to lock up - both the caliper and disc were sizzling.
Took it back to the start position and all was fine.
I believe the excessive play is due to the need for bleeding. Maybe @MotoRevive can comment.
Plus one on that, adjusted mine slightly, still lots of free play, 5 miles down the road it locked solid, disc was literally glowing red.
Caliper was clean and in good condition. Bike had only done a few thousand summer miles. As you say, multiple instances to be found by Googling.
Looking at the pictures I'd recommend stripping & cleaning the caliper & pins, looks like your caliper is sticking on the pins. The corrosion/pitting on the disc is due to parking the bike up with the brakes wet. Not an uncommon problem especially if you've ridden in the winter months. Plenty of light corrosion can be seen in your picture, all of which suggests everything needs a good strip down & clean.
One of the fronts on my 12 plate TC, started sticking,
I tried freeing it off, with no joy, my local indie , stripped the calipers, popped the pistons, cleared everything out, and normal service was resumed
no mention of year or service history so cant comment on whethers it may be a service thing
I tried freeing it off, with no joy, my local indie , stripped the calipers, popped the pistons, cleared everything out, and normal service was resumed
no mention of year or service history so cant comment on whethers it may be a service thing
picture of the master needed. i'd check that first .
read this
read this
Larry Langford
Registered user
I have that problem on my GS which was bought used, but not on my RS which was bought new. On the GS, I thought it was due to my keeping the foot over the brake, or even on it. I like a lot of slack in the rear brake so I can keep my foot touching the pedal, without activating the brake. On the GS i would notice the brake smell when i put it in the garage returning from rides. But not with the RS for some reason. So i have been riding the GS with the brake foot canted out to keep from dragging the brake. I also tried to loosen the linkage, but they didn't seem to put much adjustment there ...
I may have to revisit this and see if the caliper is sticking .....
Thanks lots of great info here ...
I may have to revisit this and see if the caliper is sticking .....
Thanks lots of great info here ...
mine would come on , all on its' own . took me 3 weeks to sus it out .
you could feel it come on on a straight flat non bumpy road ....... and then release.
i did a set of rear pads in 3 weeks ! they normally last me 2 tyres.
you could feel it come on on a straight flat non bumpy road ....... and then release.
i did a set of rear pads in 3 weeks ! they normally last me 2 tyres.
The caliper is your problem given your statement. Washing a bike twice a month may be fine in the dry summer months but leaving roadsalt on the bike is the cause of your problems. Strip & thoroughly clean the caliper, pistons, slides etc. I suspected that would be the issue looking at the disc corrosion, salt has eaten into the disc where its held under the pads.
IMHO and three GS LCs in, you need to rinse it with cold water after each ride, and flush water through the calipers. I can't imagine any modern motorcycle used every day throughout the winter wouldn't suffer. Good luck.
If you're going to ride through the winter salt. You have to be prepared for this..
If the fluid level is correct, it's probably corroded pins or more likely, piston Smeg has built up around the seals.
The profile of the caliper seals should make the pistons retreat once pressure has been released. But this can't happen if they're smegged up. So eventually the pads start dragging on the disc.
Sometimes it can be brought back to life with a PROPER clean. But often the caliper needs a rebuild with new seals.
Also.. You should not ever adjust the pedal on a BMW. There was a technical release some years ago starting that it could cause this exact issue. As the master cylinder isn't getting the correct return travel for the blowback (pressure release) hole to work..
There is also always the possibility that the rider is unknowingly activating the brake with their boot.
The pitting on the disc is most likely due to water trapped between the pads and disc which then causes corrosion and the pitting. The area affected is brake pad sized.
May just be due to a wet day or because it’s “washed after every ride” and then put away when wet.
May just be due to a wet day or because it’s “washed after every ride” and then put away when wet.
Bike was in BMW for a week, they found no corrosion on caliper, but the brake pad had somehow fused to the retaining pin, they said they had never seen it before, put it down to manufaturing defect of pads or pin. All fixed and back home now. Must admit reccieved a top service from Halliwell Jones in Chester.
well that's a weird result .
What was bringing yours on? Good result for me, fixed for free.
corrosion between the body of the master and the nylon sleeve that the piston runs in .
corrosion distorted the sleeve , and vibes/bumps would make the master apply pressure to the system , all on its' own.
corrosion distorted the sleeve , and vibes/bumps would make the master apply pressure to the system , all on its' own.
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