Rear brake disc - discolouration

[BevH]

Hello. On the ride last week I noticed a burning smell a couple of times and after I'd fallen off quite badly decided to check my bike and noticed that the rear brake disc was discoloured and wondered what I should check to make sure it's ok. I don't think it was me resting my foot on the brake as I find it has an awkward position and I would have known about it. Any advice would be appreciated. Tks Bev

[big yellow tractor]

Sounds like the break is binding.

Get the bike propped up and spin the wheel to see if it's free. You should be able (with a grunt and a fart) to move the caliper a bit on it's slides to clear the pads from the disk.

Check that the pedal has full movement up and down and that the fluid level is about right.

If the caliper is free to move now, it might be that your fluid is old and contaminated, this can cause it to heat up during compression and expand, this will make the brake bind. It's good practice to change the fluid regularly; I try to do mine annually. It's pretty straightforward to do.

I would check and re-grease your rear wheel bearings; I have known a binding brake heat the hub up enough to cause the grease to melt and get flung out of a weepy seal.

[BevH]

Tks for advice. Will check all of these things on bike when shoulder is better. Bev

[kentWR]

Check that there is not too much fluid in the system. This can cause brake binding as when it gets hot it expends and causes brake to stick on. Also dirt and muck on the piston inside the calliper can cause the brake piston not to return. I would take the caliper off the bike pump the pedal until the piston is almost out,then remove it pull the piston out clean the caliper,change the seals, new pads, bleed it through.. You should be good to go.