Rear disc brake an Avanti Aggressor

[paul33]

I have just bought an Avanti 29" Aggressor second hand, it has a noisey rear disc brake which really squeaks when the brake is applied...any idea's on what to look at to fix the problem other than oiling it!

[mitzikatzi]

Contaminated pads can do that. Clean rotors and new pads are the best way to solve the problem. You can try to clean the pads. Brake cleaner then "sand" till smooth and re bed pads.
I have read of people heating the pads till they smoke to burn off the contaminates.

If it's not that Google Avid "turkey warble"

[trailgumby]

First of all, good pickup on the bike

Secondly, what he said ^^^

Possible causes could be chain lube overspray, or even greasy fingers from someone working on your bike touching the disc and then forgetting to clean before applying brakes - did that one myself recently

Buy some automotive brake cleaner and keep a supply of clean rags handy in the workshop. Sometimes, though, the pads are beyond recovery and a new pair is the only option. Worst case could be a leaky seal, but if your brakes are Avid you can buy replacement seal kits cheaply. I wish Shimano would do that.

[paul33]

Thanks for your help....Ok but my problem is that I am working on a remote fly in mine site and NO chemicals (brake cleaner etc) are allowed any idea on cleaning the pads/ disc will general hard braking help work the nois go away as the bike was cleaned before I bought it so I guess its just cleaning liquid on the parts


Thanks

[Jean]

Metho can be used to clean the rotors too, though it probably won't help much with the pads. For those try sanding and rebedding a them if you like, but a new set would probably be the best idea.

[mitzikatzi]

Thanks for your help....Ok but my problem is that I am working on a remote fly in mine site and NO chemicals (brake cleaner etc) are allowed any idea on cleaning the pads/ disc will general hard braking help work the nois go away as the bike was cleaned before I bought it so I guess its just cleaning liquid on the parts
Thanks

We must work in different areas of the mine site. The one I work at is full of "chemicals"

The electrians will have C.R.C CO Contact Cleaner1 which would work like "brake cleaner"

Windex or Spray n Wipe will clean your rotors. A buff with steel wool won't hurt either. (After you clean rotors the brakes will be noisy till the pads are re bed in). If you can wipe with metho after the windex that would be good.

Try holding the pads with pliers and "torch" the pads with the flame from a cigarette lighter then sand before reinstalling.

Bedding brakes the Avid way

to safely achieve optimal results, remain seated on
the bike during the entire bed-in procedure.
1. Accelerate the bike to a moderate speed
(approximately 19 kilometers or 12 miles per
hour), then firmly apply the brakes until you are
at walking speed. Repeat approximately twenty
times.
2. Accelerate the bike to a faster speed
(approximately 32 kilometers or 20 miles per
hour). Then very firmly and suddenly apply the
brakes until you are at walking speed. Repeat
approximately ten times.
important: do not lock up the wheels at any point
during the bed-in procedure.
3. Allow the brakes to cool prior to any additional
riding.
this concludes the disc brake pad and rotor bed-in
procedure.

MacGyver might "sand" the pads using the concrete floor. Not saying I would do it or that you should.

[Mulger bill]

I have heard that a few minutes in a pot of boiling water will cook fluid contamination out of brake pads. Not game to try it tho', ever!

[paul33]

Hi guys and thanks for your help, I had early access to my bike just before leaving on R&R and I was able to remove them and rub them down on a concrete paving ( I know its a bush repair) as I had nothing to loose annd to my surprise it worked. I had a short ride around the bike store area and I was able to lock the brake on the dirt. So thanks again for your help
Paul