Rear Brakes

[architect]

My rear brakes are starting to squeal during low speed light braking. I notice the rear rotors get hotter than the front even though I mainly use the front brakes and of course use them harder. Just using brake cleaners to wipe down the rotor faces didn't help. I'm guessing the calipers are dirty? I've been caught in several rainy rides. Where can I order the seals and anything else needed? Preferably a Canadian can chime in. Thanks in advance.

[Evilchicken0]

As a temporary thing try thoughly hosing the caliper with cold water.

[~JM~]

Has anyone ever tried de-glazing/dressing a brake disk/rotor by attaching some super fine (like 1000 to 1500 or more grit) sandpaper on a flat sheet of glass & lightly wet sanding in a figure eight pattern? Then cleaning them well with brake cleaner. I have been contemplating on whether or not I should try this on my well used, but still smooth front R6 disks before I install new pads.

Or should I just install the new pads & call it good?

Thanks
~JM~

[pefrey]

If the rear disk is getting hot then something is dragging. I'd bleed the rear brake and replace the fluid. Then check that pistons in the caliper to see if they are retracting properly.

Lot of people just scrub brake disks with one of those green pad scrubbies. You can do it with soap and water.

Also, you might want to lightly sand the surface of the brake pads. Those can glaze over too.

[willandrip]

Has anyone ever tried de-glazing/dressing a brake disk/rotor by attaching some super fine (like 1000 to 1500 or more grit) sandpaper on a flat sheet of glass & lightly wet sanding in a figure eight pattern? Then cleaning them well with brake cleaner. I have been contemplating on whether or not I should try this on my well used, but still smooth front R6 disks before I install new pads.

Or should I just install the new pads & call it good?

Thanks
~JM~

The buttons are proud of the disc;this would prevent contact with the abrasive.(unless you have some proper fancy rotors or strip out the stock ones)
Often riders think their discs are warped when the cause is brake pad material adhered to the pad.
A good rub with steel wool will clean all debris from the surface.
When you are on,free off the buttons with a 6mm bolt,nut and washers through the button and rotated.Blow out with an airline if available.

[architect]

If the rear disk is getting hot then something is dragging. I'd bleed the rear brake and replace the fluid. Then check that pistons in the caliper to see if they are retracting properly.

Lot of people just scrub brake disks with one of those green pad scrubbies. You can do it with soap and water.

Also, you might want to lightly sand the surface of the brake pads. Those can glaze over too.

It is indeed dragging. Popped it on a stand and I get almost no free spin at all. Probably not retracting at all. Gonna take apart calipers and home seals are good and I can just clean. I'll bleed the brakes too while at it.

Sent from mobile

[architect]

So I removed pads and looked inside the calipers and they are indeed a whole of crud built up. I also notice that the wheel, even without caliper, doesn't spin as well (maybe one revolution max). Is this something to do with the alignment? Tight chain? Manual calls for about 1" of free play which seems to be small compared to other bikes. Mine has about .5" and .5" down. Without the calipers what would cause drag in the wheel spin? Thanks.

EDIT: I pumped the brakes a few times and notice one piston is pushing out but not the other. I'm guessing both should push out at the same time so either the other one is seized or just gunked up.

[GreyImport]

Clean off all the crap then try to press the pistons all the way in (remembering it will push fluid back up the system ) ...... then see if they will push out together.... do it a few times.

I use something like this to push the piston in evenly ...

http://www.ebay.com.au/itm/1-Pair-18-37 ... 337c8b6b89


Pull the chain off the sprocket so the wheel can spin of its own accord......if its still tight then its time to pull off the wheel and check the wheel bearings.