Mountain Biking - Help with Rear Disc Brakes

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View Full Version : Help with Rear Disc Brakes


KiaTia
07-17-08, 08:12 PM
Help I got a little carried away cleaning my bike and I think I got some WD 40 on my rear disc and now I have no rear brakes at all! These are 3 or 4 year old Hayes units do I need new pads or what can I do to fix them? I tried using carb cleaner on the disc and the pads but all that did was make them bark like a duck and still no braking.

Thanks
Mike


ed
07-17-08, 08:18 PM
Help I got a little carried away cleaning my bike and I think I got some WD 40 on my rear disc and now I have no rear brakes at all! These are 3 or 4 year old Hayes units do I need new pads or what can I do to fix them? I tried using carb cleaner on the disc and the pads but all that did was make them bark like a duck and still no braking.

Thanks
Mike

Clean the rotor and buy new pads.

ca7erham
07-17-08, 08:29 PM
Clean the rotor and buy new pads.

I've soaked V-brake pads in water for a day or so after doing a similar thing, would that work for disc pads?

Also why use WD-40? IMO it doesnt work too well on bikes (or most things for that matter) and now they use CO2 so it doesnt burn too well. So whats the point of getting/using it?


grundle rider X
07-17-08, 08:33 PM
I've soaked V-brake pads in water for a day or so after doing a similar thing, would that work for disc pads?

Think...are V brake pads and disc brake pads made of the same material?

Clean the rotor and buy new pads. Or bake the contaminated pads at high temp for 30 minutes/take a torch to them to burn off the oil from the WD40 and then try them again. Most likely you will still end up buying new pads.

ca7erham
07-17-08, 08:45 PM
Think

Damn, do I have to?

No, but really what you said makes sense. Find the steepest hill you can (of a flat streach of road with a tail wind), go as fast as you can and brake using only your rear brake and reapeat so that your brakes get hot (or do as grundle said, but be careful not to fry your pads)

BenLi
07-17-08, 10:15 PM
Clean the rotor and buy new pads.

Cheaper alternative: sand the pads.

grundle rider X
07-17-08, 10:17 PM
Cheaper alternative: sand the pads.

Please explain how sanding the surface of the pad removes the contaminants that have penetrated the other portions of the pad material.

Thanks in advance.

Rodney Strong
07-17-08, 10:50 PM
:notamused:
Help I got a little carried away cleaning my bike and I think I got some WD 40 on my rear disc and now I have no rear brakes at all! These are 3 or 4 year old Hayes units do I need new pads or what can I do to fix them? I tried using carb cleaner on the disc and the pads but all that did was make them bark like a duck and still no braking.

Thanks
MikeNew rotor: $30. New Pads: $20. Bite the bullet. Chalk it up to experience. Or you can mess with the half *** solutions in a vain attempt to save $20 spent three times over a month. Been there.

cryptid01
07-18-08, 05:27 PM
:notamused:New rotor: $30. New Pads: $20. Bite the bullet. Chalk it up to experience. Or you can mess with the half *** solutions in a vain attempt to save $20 spent three times over a month.

This rings true with the exception of the need for a new rotor. That and the needless asterisking of "ass" which was both amusing and in violation of forum guidelines.

Just hit your rotor with some non-chlorinated brake cleaner from your local auto parts place. Or if you'd prefer to support a bike industry co., there's White Lightning Clean Streak (http://www.whitelightningco.com/products/clean-streak.htm).

ed
07-18-08, 05:36 PM
This rings true with the exception of the need for a new rotor. That and the needless asterisking of "ass" which was both amusing and in violation of forum guidelines.

Just hit your rotor with some non-chlorinated brake cleaner from your local auto parts place. Or if you'd prefer to support a bike industry co., there's White Lightning Clean Streak (http://www.whitelightningco.com/products/clean-streak.htm).

Umm...yeah, I wasn't understanding the need for new rotors.

Rodney Strong
07-18-08, 09:38 PM
This rings true with the exception of the need for a new rotor. That and the needless asterisking of "ass" which was both amusing and in violation of forum guidelines.

.Guess I am used to forums where a*s is not bliped out. As a church goer I am not offended by the word used to describe a relative of the horse or part of the human anatomy. Dang the word is used in the Bible. But hey, I am a team player, Arse it will be. :D

Edit: Second thought. Not everyone can afford to just buy new rotors. So yea trying the cleaning option makes sense. But if that doesn't work...........

Hot Rod Lincoln
07-18-08, 10:21 PM
Guess I am used to forums where a*s is not bliped out. As a church goer I am not offended by the word used to describe a relative of the horse or part of the human anatomy. Dang the word is used in the Bible. But hey, I am a team player, Arse it will be. :D

Edit: Second thought. Not everyone can afford to just buy new rotors. So yea trying the cleaning option makes sense. But if that doesn't work...........

Your recommendation to just buy new pads is about the only thing that will really work...rotors could probably be cleaned well enough but the pads are toast.....

kill.cactus
07-19-08, 10:32 AM
:notamused:New rotor: $30. New Pads: $20. Bite the bullet. Chalk it up to experience. Or you can mess with the half *** solutions in a vain attempt to save $20 spent three times over a month. Been there.

I've had the same happen.

Bake the pads at your LBS (they'll have the torch and should do it for like 5 dollars), then soak the rotors in rubbing alcohol. That is what I did and it worked well.

Total fix it cost: 5 dollars + rubbing alcohol (70 percent).

Cheeto
07-19-08, 10:52 AM
I've had the same happen.

Bake the pads at your LBS (they'll have the torch and should do it for like 5 dollars), then soak the rotors in rubbing alcohol. That is what I did and it worked well.

Total fix it cost: 5 dollars + rubbing alcohol (70 percent).

I was just about to suggest the Rubbing alcohol...... beat me to it.
Although, Only stuff I have is the like 90 something percent.

KiaTia
07-21-08, 10:19 AM
UPDATE

Got new pads and cleaned the rotor with alcohol. The new pads work but not as good as the old ones before the W40. I guess they will have to be broke in I only have about 8 miles on them. Thanks for all the help.

ed
07-21-08, 11:48 AM
Yah...give them time to burnish.