Disk brakes and cold weather

instinct

Hey, I am just wondering if its the cold that is effecting my brakes. They just seem to squeal and not a lot of stopping power. I even bought some brake disk cleaner and sanded the pads just to make sure they were okay but still squealing away this morning.

Hydraulic BTW

Pigeon Reaper

An old trick on motorbikes with squealing brakes is to apply copper grease to the back of the pad(do not put anything on the friction side) This helps to stop the squealing which is normally caused by the pad vibrating against the piston. Don't use anything but high temp grease otherwise it might melt onto the discs which is a very bad thing. It should work just as well with bicycle hydraulics too.

CheGuedara

Well squeaking is def most frequently due to contamination of the disc or brake pads but IIRC if some disc brakes get very cold then the rubber seals around the pistons could get stif and could possibly allow a little brake fluid past them or air into the system - still shouldn't be a lot. Do they still squeak badly at the bottom of a good descent/long cycle which should see them warmed up?

instinct

no, if I can get a good run down a long hill (Howth) and keep the rear brake applied it eventually heats up and then there is plenty of bite after that.

Just since the snow and the cold temps the brakes seem really poor and after cleaning them the other night and adjusting the levers I was hoping they would be fine this morning.

How about bleeding them ? Should that help ?

And thanks, I might try the copper grease trick.

Gavin

Having the same problem on XTs actually. Horrendous wailing coming from them and poor grip.

CheGuedara

instinct wrote: »

no, if I can get a good run down a long hill (Howth) and keep the rear brake applied it eventually heats up and then there is plenty of bite after that.

Just since the snow and the cold temps the brakes seem really poor and after cleaning them the other night and adjusting the levers I was hoping they would be fine this morning.

How about bleeding them ? Should that help ?

And thanks, I might try the copper grease trick.

Hmm, sounds like just a cold weather effect alright so.

If you can bring the bike into the house o/n so that it's warm before you take it out the next morning and if it's sqeaking less then that could go a ways to testing the theory at the max cost of a slightly miffled o/h.

Just unleashed the google-fu and found THIS from Nov of this year - sounds like a common enough issue and seems like bleeding the system could be a good idea for a quick fix

instinct

thanks for that. It does seem like the cold is having a negative effect and hopefully a bleed will get the air out. I have noticed similar after leaving the bike hang in the shed for some time. Again it could be air in the system.

the lads in the shop were I got the bike serviced said to drop in and take a look. He suggested new brake pads but the ones in it are not on that long and as I cleaned the disks there is not much more to look at.

They checked the fluid level at the service but didn't bleed. But looking at the forecast, the bike may be going back in the shed for another while