My cycle has got an front disc brake I not know how but unfortunately few drops of oil got on my disc brake now it was making a very bad sound like a violen and and could even not able to stop my cycle at all now I have only one way to fix it,s you please help me
alcohol, specifically isopropyl alcohol, aka isopropanol– PeteHDec 9, 2015 at 13:18
Is denatured alcohol bad to use for this purpose?– BenzoDec 9, 2015 at 17:26
I use Carplan Brake and Parts Cleaner, purchased from my local auto parts shop. This contains about 30% IPA (isopropanol) and 70% Naptha.
If you don't have many bikes, it may be easier to visit your local car mechanics' workshop and ask to use a little of theirs.
If you have contaminated the rotor, you will also have contaminated pads. There is a procedure to restore pads using brake cleaner, an oven and a blowtorch... This isn't worth the effort and risk, so buy new pads.
You don't have to buy your caliper manufacturer's own pads, so long as they're the right shape; I've had no problems using Clarks and Ashima pads.
I've never owned disks, if the OP got oil on the disk and then spun the wheel but didn't apply the brakes, would the pads be contaminated? I'm imagining a spill while doing a service and not being ridden.– Criggie ♦Dec 9, 2015 at 20:29
4He said there's squeal, so he's braked.– EmyrDec 9, 2015 at 20:33
The disc is the easy problem - as already suggest, brake cleaner, alcohol, methylated spirits all work well. An abrasive (scouring) household cleaner also works really well.
The pads are another problem altogether as they absorb the oil. If you can afford it, by far the best solution is to replace them. If you want to try to save them you need to remove them from the brake and give them a really good clean. Put them in a container with solvent and let it soak in, then wipe off and sand/file the surface layer off - again, an abrasive cleaner can be used effectively. Some people suggest trying to burn the oil off - place on a metal tray in a safe place, a couple of drops of meths on the pad, and light it.
1The "wet" boiling point of DOT4 brake fluid is 155 °C (311 °F). This will apply as the fluid will have absorbed water. The base of the flame will not be the hottest part and when the fuel is Ethanol, may not be hot enough to reliably vaporise the oils. The presence of water will cool the flame. The coldest viable Ethanol flame is also likely to leave a sooty residue and inefficient combustion of brake fluid will also leave soot. The procedure I mentioned in my answer involves heating the pads in a domestic oven then burning the hot pads with a blowtorch. Reliable but dangerous.– EmyrDec 10, 2015 at 11:03
There are many ways to remove grease/oil from a rotor at home. A simple degreaser will do the trick. Make sure to use a towel that doesn't already have grease on it. If the degreaser isn't cutting it, you can move on to using ethanol or isopropyl alcohol, which most people have in the house. If you are still having a hard time, try pure acetone (nail polish remover). Get the non scented, non colored kind. It's usually less than a dollar for a bottle at the pharmacy. I'd also suggest using rubber gloves to protect your skin while using any of these chemicals.
1Why is isopropyl stronger than a degreaser?– DetJul 18, 2017 at 8:31
I would actually be worried that the degreaser causes even more contamination. You must know what kind of chemical it is. After all, WD40 is also a degreaser. Jun 19, 2019 at 11:46