Help needed urgently

[AlanAce1967]

Hi Guys,
im due to go to Scotland Friday morning but have a problem that needs sorting.
I changed my rear brake disc a couple of weeks ago and the brake pads at the same time. Since then the rear disc and caliper and rear hub has been getting very hot. I thought it was the cheap brake pads i got off ebay as the brakes dont appear to be binding so i went to BMW last night and bought the real deal and fitted them thinking problem solved, WRONG !
Got to work this morning and the disc was a blue colour with the heat and the caliper etc was also very hot. Whats going on ? The brakes are not binding, what else could cause that problem ?

Alan

 

[D6]

besides u keepin your foot on the brake, nothing, they must be binding

 

[AlanAce1967]

I was wondering if it could be anything else and the brake pads were just coincidence, like rear wheel bearing or something ?

 

[Mort]

Did you also fit a cheap disc? perhaps it's getting hot just through normal use.

 

[PIGGLET]

If it only started after you fitted the disc and pads then they will be the cause.
I would hazard a guess that the by fitting the new disc and pads the pistons in the caliper will have been pushed back in to a point they haven't been to in a long time and will be sticking/binding. Maybe only slightly but it could be enough.
Remove the caliper and pads and carefully push out the pistons a bit at a time using the brake pedal (don't go too far or you'll pop the pistons out).
Clean the pistons with WD40 and push them back into the caliper.
Repeat untill they fully recess/seat and do so in a smooth manner with minimum force.

 

[ianboydsnr]

make sure the sliders slide and the pads are free to slide

 

[Packer]

Also check that the wheel and disc are running true.

If you have a stone or something wedged between the wheel and the final drive face or the disc is not mounted true the disc will be running "off" and will be pushing the pads back and forward constantly as you ride rubbing first one face and then the other. This could cause substantial heat build up.

If you have a dial gauge check the disc run-out. If you don't then put the bike on the centre stand and hold a strip of softwood on the top of the swing arm and gently turn the rear wheel to make sure that the disk is rubbing evenly against the wood throughout a full turn of the wheel.

It may of course be a sub-standard disc with run-out, same result.

I don't think that a faulty bearing could cause enough heat to blue a disc without the oil in the hub igniting first.

 

[Steptoe]

I changed my rear brake disc a couple of weeks ago and the brake pads at the same time. (

Is the disc a grimeca

Check the caliper is sliding on it's pins. Push the caliper by hand or with your foot towards the wheel. It should open up the pads and the wheel is free to spin.
Then pump the lever a few times so the brake pads are fully extended, and spin the rear wheel again this time to check if it spins freely .

 

[Dragon Master]

This might be a daft question, but have you got the disc on the right way round? I managed to put one on the wrong way myself. (I did say 'daft' )

I worked it out before I got to riding, but it would certainly have caused over heating if I hadn't...

 

[AlanAce1967]

Well i took it all apart again checked everything and put all back together, it freewheels better now so ill see how it goes this morning.

Thanks for all your comments.

 

[Steptoe]

This might be a daft question, but have you got the disc on the right way round? I managed to put one on the wrong way myself. (I did say 'daft' )

I worked it out before I got to riding, but it would certainly have caused over heating if I hadn't...

The disc mounting holes have recesses for the mounting bolts to fit into so they don't protrude - so you can't fit the disc the wrong way around and put the wheel back on, because the bolts would touch the final drive housing.