do you think that I could use Shimano mineral oil on/in Hayes Nine Hydro brakes (where it says Dot 4).

Thanks for your help people!

  • bicycles.stackexchange.com/questions/49827/… Commented Oct 9, 2017 at 15:53
  • Out of curiosity, where are you that mineral oil is easier to get than DOT4?
    – alex
    Commented Oct 10, 2017 at 3:20
  • only because I have some mineral one / shimano in the house, instead I will need to buy the Dot 4. I will move house soon and often I bought bottles and then did not use them more then once. Dot 4 is very easy to find anyway. Commented Oct 10, 2017 at 7:54

3 Answers 3


No. Can not, must not. Fluid type mismatches in either direction can make seals and other non-metal parts degrade, swell, and/or fail. Mineral oil, being the less caustic and reactive one, will generally do it more gradually when this mistake does get made, but it still does it or at least can.

  • I imagined so, that there was an effect on the seals and so to safety, and I appreciate your input, thanks Commented Oct 10, 2017 at 7:52

Not if you want the brakes to continue working normally, No.

Manufacturers design their brake systems to work with a specific kind of fluid. Mineral oil and DOT fluid have different properties and are not interchangeable.

In your case (putting mineral oil in a DOT system) I believe the seals may/can swell and the brakes will become unusable.

  • Thanks a lot I appreciate it. And as someone asked Dot 4 is easy to find everywhere, more than shimano. Thanks everybody Commented Oct 10, 2017 at 7:53

Using LHM+ liquid for all my shimano brakes (3 bikes in a house) for last two years (started using as a winter oil, because shimano's one had problems). It is cheap, and it has no problems in winter (in my climate, temperature can drop to -10 °C).

LHM+ is some way better than DOT4 in low temperatures and it it little more 'softer'

No problems yet.

But do it on your own risk.

  • Of course, any change you do, then you ride it and it is at your own risk. Commented Oct 16, 2017 at 18:07
  • I live in Estonia, it gets very cold here and grease (like in hubs) should not be too much because it freezes. I like shimano oil because it is organic and do not ruin components over time. In this case I had some so I was thinking to try shimano on hayes. I ended up asking a shop to sell to me just a tiny bit, and they did, spending just 1 euro. On the other hand servicing hayes without the right tools was hard(er). Commented Oct 16, 2017 at 18:09

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