These brake pads were basically black before I cleaned it off with alcohol. I lightly sanded after I cleaned them but when I put it back together and tried to ride, it still squeaks loudly when I stop from a slow roll. Do I need to clean these more? Sand more?
by lazormajor
15 Comments
Maybe try torching. You can use a blowtorch or even just a lighter – recommend a zippo or a bbq one so you can get some good heat on it without burning your thumb.
I would sand. Also you see that line on the left? Your disc itself could have a groove, that could cause it as well.
I’d look at why they’re wearing so unevenly first… might be part of the problem.
May also be worth just getting new pads, when the rears on my bike squeaked (secondhand purchase) I’d tried cleaning with alcohol, acetone, sanding pads/rotor, torching, adjusting calipers, etc multiple times…. Nothing worked for more than a few miles.
New pads have been fine for the last few hundred miles
Sand them a little to try and remove the contamination
Well no wonder IPA is far too hoppy /s
Hows your alignment looking? Based off the wear they dont look like they were making contact with the disc correctly to begin with. Should make full contact across the whole pad when touching
Break pads are not easy to decontaminate. At the shop, we never mess around with it. We just clean the rotor with Dawn HD dish detergent, and replace the pads.
The friction material of a brake pad is very porous. So, when they become contaminated, the contaminant seeps into the pad. Sanding will not remove it. Contamination is not surface deep.
Do you have sponge at home? Drip some olive oil into it. Now, try and remove that oil with sand paper. Doesn’t make any sense, does it. The same thing is going on with these brake pads.
Using a blow torch can work, depending on the contamination. It is sometimes possible to boil or smoke the contaminant out of the pads, but not always.
Your pads could also be squeaking because of the wheels, but that is uncommon. For example, high tension wheels, usually built with carbon spokes, can squeal like you are describing. The brake pads cause vibration, and if that lines up with the resonate frequency of the spokes, you’ll hear them.
My advice to you? Take the rotors off the bike, clean with dish soap, and replace the pads with the L04C-MF, the metal compound. I’ve had a lot of success quieting bikes down with metal pads.
And that’s why I hate India Pale Ales, they are good for nothing.
Sand, isopropyl alcohol, heat them up (hold them with tongs over a blowtorch, stovetop, or something similar). They will smoke, especially if they have oil in the pads, so make sure you have proper ventilation. Bed in your brakes properly.
If that doesn’t work, do it again, plus do the same to the rotors.
If that doesn’t work, buy new pads for $10USD.
If that doesn’t work, you likely have a leaky caliper (assuming you have hydraulic disc brakes and not cable/mechanical disc brakes) that must be fixed/replaced.
To identify a leaky caliper, clean the calipers and pads well with isopropyl alcohol. Put a rubber band over your brake lever tightly and leave it overnight. Take out the pads and inspect everything very carefully. If you see/feel any oil, that means your calipers are leaking.
Went through this whole process myself recently (very frustrating). After I left it overnight with the brake lever pressed, I could clearly see circles of oil on the backs of my brake pads in the shape of the pistons.
Have you tried a lager instead. Seriously, maybe it’s your rotors as well. I heard from my mechanic that he sometimes lights the ipa on fire to burn anything off .
I really set myself up with IPA lol. Gonna try some stouts and lagers like some of you suggested. Thanks for the good laugh
Are your disc rotors warped? The pad wear looks uneven.
Take off your discs and lay them flat on a table.
Pads absorb fluids. If sanding them didn’t help from them being glazed, you’ll probably need to replace them. Make sure and clean your rotors thoroughly. I would aggressively sand ten with some 100-grit.
Lightly sand your disc too. Both sides where the pads clamp on
replace the pads. if you feel a nice groove in the rotor. replace that too. if basic cleaning doesn’t do it, forget about it.
They don’t look unevenly worn to me, shimano pads have an angled cut at the base of the pad material. Get some actual brake cleaner, clean the rotors also using some light abrasive like steel wool or a scotch Brite pad. Then clean the pads using the brake cleaner. After that you need to re-bed the brakes, go down a hill pulsing your brakes on and off a couple times, that should stop the squeal. If that doesnt fix it then get new pads.