Disc brake sticking on

gee23

Hi i have Formula ora brakes, the back brake has started sticking on if left in the sun. First time i noticed it was when i got back from ride washed bike and left in sun to dry but it has happened twice since then once at work and yesterday while i was putting new tyres on did the back wheel first everything ok when i put wheel back in, did the front wheel by the time i put front wheel back on the rear brake had looked on put bike back in garage tried it later and brakes had loosened of again can someone help thanks.

nicklouse

how old are they?

gee23

Just over a year old and they work fine when riding.

nicklouse

maybe just over filled with fluid.

or the pistons have just moved (as the pads wear) and are closer to the rotor than before.

dan shard

Coefficient of thermal linear expansion. As a fluid heats up, it increases in volume. As said previously, pistons too close or too much fluid will cause it

gee23

Brakes were on bike from new, and this only happens if bike is left in sun not when riding thanks for help will get them checked out

nicklouse

dan shard wrote:

Coefficient of thermal linear expansion. As a fluid heats up, it increases in volume. As said previously, pistons too close or too much fluid will cause it

the heat should not do it as the fluid gets a lot more heat put into it during use.

but Air or Water would be my culprits.

get them bled.

Radioactiveman

Had this before whilst MTB in spain, turned out the caliper needing blleding. The small amount of air in the fluid expanded and effectively locked the caliper. I would bleed it and see how it goes.

gee23

Will do thanks