So I was stupid enough to get a fair bit of WD40 on my disk brakes. I tried cleaning them by removing the wheel, cleaning the disk (with soap) and to spray soap in between the brake pads and wiping it with a small cloth.

However, the brakes still squeak like crazy. Does anyone have suggestions on how to fix this?

I went to a bike shop and they told me I would also need to replace the rotor disks, is this true?


2 Answers 2


You should get rid of the pads and buy new ones. You can clean the disc with cleaning alcohol or brake cleaner. Just be sure to also clean all holes from the inside as there might be some oil left.

Afterwards bed in the new brake pads and you are good to go.

  • Can’t you just wait for the oil to boil off or otherwise disappear? I was surprised how little impact oil has on rim brakes and how quickly it disappears.
    – Michael
    Jun 19, 2019 at 11:12
  • No it will settle into the brake pads and you will get the same problem again. Brake Pads and Brake Shoes are from completly different materials.
    – nollak
    Jun 19, 2019 at 11:27
  • @Michael, no you cant. Oil does not evaporate, and soaks into the disc brake pads. Brake contamination is serious safety issue and needed to be addressed immediately. Jun 19, 2019 at 11:30

Second part - you do not need to replace the rotor assuming its not worn out.

However you need to clean it properly. To do that I'd remove rotor from wheel, and clean every hole with degreaser or similar. Use an old tooth brush to get everywhere.

Dry it with paper towels, and absolutely refrain from touching it with bare hands or dirty gloves. Treat it like dentistry equipment.

actually boiling it in a pressurised autoclave might be a superlative way of cleaning - but I've not tried this. An ultrasonic bath cleaner might work too, again YMMV

While rotor is off the bike, give your hub and spokes a good cleaning too. There's very likely oil on the hub which could migrate out, ruining all your good cleaning work.

Once its clean and dry, refit to the bike. Use new bolts if the old ones are damaged at all, and remember some hand loctite on the threads.

As a corollory, find some way to stop this happening again. It might be as simple as two clean rags over the disks when you use any form of aerosol or spray.

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