Rear brake drag?

Hi all,i am looking into a problem on the 2000 mdl 5th gen rear brake.I noticed that when i stopped to check tire pressure that the rear wheel was hot and the rear disc was really hot.Even though i wasn`t using the rear prior to stopping?
I know that the brakes are linked ,but the fronts weren`t hot at all?
I then pulled the caliper off at home and cleaned it.I put in silicon brake grease on the sliders and the pad pin.All of which were in really great condition.The pads are clean and have heaps of life left in them.After riding it i think it was slightly better but still getting hot.
My next task is maybe bleeding the rear,but having read the manual it looks like a pain.
Any other thoughts before i cover the garage, bike,and me in brake fluid???

 

Are you resting your foot on the lever when riding? It requires quite a bit of force to make calipers press pads into the rotor; either it's maladjusted or something's pressing.

 

I have been very careful to keep my foot off the lever just to make sure.So it is not that.

 

rotor width isn't worn out of spec is it? Possibly warped?


Have you tried pushing the pistons all the way in and trying again?


If that doesn't work...then looks like you'll have to bleed the brakes or rebuild the caliper which means you get to bleed the brakes anyway...lucky you

 

I haven`t checked the warp factor,but when i spin the wheel it makes the same noise all the way around.So i guess that it is o.k.:smile:

 

I have to agree with the D man, I think its a sticky caliper piston.sometimes you can spray a little wd-40 or something around the piston seals,being careful not to get WD 40 on the brake pads or rotor. Let the lube soak in for a few minutes and with the bike on the stand apply good rear brake pressure and let off,do this 4-5 times. You should see an improvement. If no better ,than try bleeding the rear caliper,if still no better rebuild the caliper
paying attention to piston fit. eddie

 

Thanks for the advice guys.I will have another go at cleaning/freeing up the pistons.Although they looked in great shape anyway.But can anyone else tell me if their rear rim gets really hot after a long ride without using the rear brake?

 

HeyJolly; I have a y2k vfr and my rear rotor & caliper are warm after riding ,but not so hot as you cannot touch it. I know that is not very specific,wish I had it running so I could give you a direct read from my infa- red temp gauge. edddie

 

Have you tried opening the bleeder when the rotor and caliper are hot to see if you have system pressure building up?

 

You've tried most of the regular fixes....

make sure the rear brake Mc has adequate freeplay at the lever, about 2-4mm before contact??

THE rod going into mc is adjustable, yes adjustable., so try making it a bit shorter.

 

i have tried cleaning the caliper again and i looked into the piston movement and was a little surprised at the two outer pistons moving quite well,but the inner not moving until a much greater peddle pressure.And YES I DO know that the brake system is linked,and the front brake actuates the rear middle piston as well.But i assume that the rear is surposed to push all three pistons at the same time??
Although the piston sizes are different,so that would explain why more pressure is needed for the larger one.Is my back brake normal?
Can someone tell me to just put it back together and stop fussing with it!!:smile:
Or perhaps i just need to get a life??

 

I am having the same problem, disc too hot to touch, although the wheel is turning freely when on the centre stand.

I have replaced the rear pads and cleaned the pistons, they seem to be moving in and out freely. When pressing the pedal the two outside pistons come out first, then the middle one.

However, when I squeeze the front lever, I get nothing to the back wheel, it still turns freely, but when I press the foot pedal, both front and back brakes are applied....

Any advice?

 

I still havent got to the bottom of my problem yet.But i have bleed the brakes,and they are still the same.Hot at the rear.
All i can suggest is that your pcv or the delay valve may be faulty.Or perhaps they just need bleeding?The problem with this system is that when it works it`s great.But to fault find is very hard and time consuming.
Best of luck!

 

i noticed the other day that my rear rotor get hot also, but you can still touch it. my bike is a lot older than your and i suspect that the seals are just bad.

is it difficult to rebuild the calipers?

 

I haven't rebuilt any bike calipers, but have done cage calipers, resealing wasn't too hard on those. I just got a reseal kit that included all the rubber bits for the caliper and some brake grease, force the pistons out with compressed air, clean and inspect it all, replace the rubber parts and reassemble. The problem I had on my cage calipers was the exposed part of the pistons had rusted a little bit, and then when forced back into the seals it made them stick.