Yet another wd-40 problem – bike forums 10 gases

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Hey, I’ve got myself a new used bicycle with hydraulic brakes. The bike was cleaned before selling so the brakes were very squeaky. I didn’t know that the squeaking would go off after some miles, so when fixing the bike up my friend told me to use WD-40 on my whole so I did so. Now my brakes have been squeaking without stopping ever since. Every time I wash my disc with water it stops from squeaking for about 1-2 minutes, but then starts again. I’ve read to change the pads so I did. I cleaned the disc off and I put the new pads. They weren’t squeaking but after some time of testing brakes they started again. I don’t know if it’s because they are fresh pads, but I don’t think so and I’ve lost all hope. What do I do now? By the way the brakes aren’t good, they are stopping very slow. And yes I did overspray WD-40 on my front system, but it happens in the back too. I’ve taken my bike to the local bike shop (my city doesn’t have professionals or anything) and they just suggested me putting new pads OR changing the whole braking system. Also how do I adjust the brakes? One of the pads is all time on the rotor. Both old and the new pads are shimano B01S resin pads.

Hey, I’ve got myself a new used bicycle with hydraulic brakes. The bike was cleaned before selling so the brakes were very squeaky. I didn’t know that the squeaking would go off after some miles, so when fixing the bike up my friend told me to use WD-40 on my whole so I did so. Now my brakes have been squeaking without stopping ever since. Every time I wash my disc with water it stops from squeaking for about 1-2 minutes, but then starts again. I’ve read to change the pads so I did. I cleaned the disc off and I put the new pads. They weren’t squeaking but after some time of testing brakes they started again. I don’t know if it’s because they are fresh pads, but I don’t think so and I’ve lost all hope. What do I do now? By the way the brakes aren’t good, they are stopping very slow. And yes I did overspray WD-40 on my front system, but it happens in the back too. I’ve taken my bike to the local bike shop (my city doesn’t have professionals or anything) and they just suggested me putting new pads OR changing the whole braking system. Also how do I adjust the brakes? One of the pads is all time on the rotor. Both old and the new pads are shimano B01S resin pads.

image1 – imgur.com/fSHbceP (sorry I know that I shouldn’t post links until I can get 10 posts, but this problem is really frustrating and I want to get it fixed ASAP and finally ride the bike I bought)Many, many, many people assume that WD40 is just a solvent and not a lubricant. They are all very wrong. WD40 contains 25% mineral oil which is a lubricant, aka oil. You’ve sprayed oil all over your brakes and, as you are finding, brakes don’t work all that well when lubricated.

You need to clean the rotors with mineral spirits…aka white spirits, naphtha, white gas…or brake cleaner to remove the oil for the rotor. Alcohol won’t work. And, no, mineral spirits won’t leave "oil" on the rotor. Don’t use kerosene or diesel either.

The pads are toast. Disc brake pads are somewhat porous so any oil on them penetrates into the pad material. You can’t really wash it out or remove it from the surface because the oil is below the surface. It’s the gift that keeps on giving. You might be able to wear the oil off but, most likely, you’ll have to wear the pads down to nubbins and endure poor braking the whole time. Just replace them and learn from the experience.

Spirits can be alcohol sometimes. But more often in the mechanical side of things, if the conversation includes "spirits" I’m going to imagine you are taking about mineral spirits. Which is not ideal for the final cleaning of brake pads on a plane, car or bike IMO.

Alcohol in the form of ethanol, isopropyl or methanol (there are good and bad about each of these types, but thats a different conversation) is what you want to use for cleaning brake pads and disks. If they are mucked up with grease, mud, grime of any sort, use whatever takes that off easily. But use alcohol for the final cleaning to get the last of the residues that will cause them to squeal.I’m fastidious about saying "mineral spirits" and never use the term "spirits" to describe alcohol…whether that is ethanol, isopropyl alcohol (or, more correctly, 2-propanol) or methanol. I may, on rare occasion, refer to ethanol as "alcohol" because that’s what most people understand ethanol to be. I may on less rare occasion refer to isopropyl alcohol as "rubbing alcohol" because, again, that’s what people are used to calling it.

Mineral spirits…not kerosene nor diesel… is ideal for cleaning rotors (you don’t clean the pads), especially in this instance. The problem that vytka has gotten into is that there is mineral oil on the rotors and pads. Mineral oil is nonpolar as is mineral oil. They are different distillation cuts of a similar material to mineral spirits. They just have a higher molecular weight which makes them more viscous and less volatile. Mineral oils don’t dissolve all that well in alcohols unless you get up into the butanols which start to have an oiliness of their own.

Mineral spirits evaporate cleanly and don’t leave behind any residue. There’s no need for using alcohol as a "final rinse" since it doesn’t do anything. Brake cleaners that aren’t chlorinate hydrocarbon based are mixtures of mineral spirits (85 to 90%) and perhaps some alcohol (15%) but the major lifting is being done by the mineral spirits which, again, evaporate cleanly.