braking issus

[Random13]

good evening,

my disc brakes do get hot I think more often these day ( no surprise , hot weather) but also the disc color has changed form garyish to more like a red/grey color which i think happens when it is hot but seems to stay that color even after it cools down .


couple of basic questions,

1.do i need to clean the brake disc as a maintenance ? in another word does road dirts and brake pad material stick to the disc making the contact between the pad and disc less thus less friction resulting in worse braking performance ?

2. my brake pads have started to make a squeeking sound , is that due to the copper grease on back of the plates drying out or sign or a more serious problem ?

3. the brake seems to be worse when the bike is cold and riding in the morning and as I brake few times it gets better . it sort of feels that the pistons are pushed back out when braking when the disc is cold so I have to brake harder to get the same performance of when the disc is hot after a 1/2 mile of riding .

4. when do you change your pad? when it gets down to having nothing ( the metal bit ) ? does the braking performance gets worse with less pad or brake pad wear?

here is a picture of my pads which I am not sure how much it has got left as the brand new ones seems to be very thing so hard to say how much it has got left ,

https://i59.tinypic.com/5xk6kn.jpg


many thanks for your help

[P.addy]

I'd probably order another set now.

I'd also strip and clean those calipers, if they are getting proper hot, I'd expect some form of movement is now restricted and dragging the pads on the disk without having the brakes on.

[Bunny Lingus]

Sounds like it definitely needs a coat of looking at. Can't view the pic but some brake pads have a vertical scored line running through the friction material. Change the pads when the friction material wears to, or pref just before the score mark. What bike is it? Had an old Guzzi that sported discs that would rust before your very eyes after only one day of non use. Red dust everywhere, forks, wheels, alternator cover, you name it...
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Bunny Lingus & The Flipside Faggots

[Kickstart]

Hi

Looks like quite a bit still left on those pads.

Disks generally don't need cleaning off. Unless someone has got oil on them.

The squeak is probably the pads.

Some pads work better when warm. The worry would be if the pads are dragging on the dis (ie, caliper sticking so they drag)

However what pads are currently in the caliper? The slightly odd brake performance reminds me a bit of how the Bandits brakes behaved with some Armstrong pads in there (they were great when new and lasted for ever, but after about the normal expected life of a set of pads the performance tailed off badly).

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Random13]

I changed the piston seals recently so don't think it is sticking .

I guess to verify , I lift the front move the wheel and there should be no drag ,right ?

re cleaning caliper do you mean to simply disassemble and clean with washing liquid?

what would you use to clean the disc ?

thanks

[Kickstart]

Hi

To clean the caliper (if required), get some brake cleaner (5L non aerosol can is pretty cheap) and a toothbrush. Caliper off, pads out and give the pistons a good clean (pump them out a touch). Then push the pistons back in, pads back in , caliper back on and pump the lever a bit. If they drag after that then they need a proper strip down (ie, pistons out and clean behind the seals).

You should be able to spin the wheel and have no real drag. The pads will lightly touch the surface and you will hear that, but they shouldn't be noticeably slowing the wheel unless you have the lever pulled.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[TUG]

[Random13]

hi all,
I did clean the discs by simply wiping a toilet tissue over it and some gray material which I guess is the brake pad that has melted on it did come off after which the performance of the brake was way better.

now after further inspection I think the disc is scratched as if someone has scratched it with knife perfectly in a round shape which suggest that the brake pad has done it .

by how can it do that when it has a plenty of pad left ?

I am changing it now but very curious .

re rebuilding it , I did change the seals and cleaned the piston as much as I could. It was not rusted but did just do a service on it .

is EBC pad the best out there?