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DOT oil in Shimano brakes


This topic contains 5 replies, has 4 voices, and was last updated by  Canadmos 11 months, 3 weeks ago.

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    Matt Bingham

    I just bled my new brakes and I’m worried I may have used DOT oil. The brakes work, but not sure if it was mineral. I bought a bleed kit and I thought it only came with mineral oil, BUT now I’m worried it came with DOT and Mineral. The bottle was not labeled.

    The oil I used was red and thicker than the mineral oil I also found (blue).

    Is there a way to test the oil to see if its mineral? Water soluble?

    If I did use DOT, can I flush the system and save the brakes? They have worked well (only used for one ride)

    Santa Cruz



    Did you use a Shimano branded bleed kit or something else? Shimano only uses mineral oil, and it is red.


    Matt Bingham

    Nope not Shimano. I have a feeling it’s actually mineral oil. Just thicker.


    Renegade Hardware

    Shimano mineral oil is light red.

    Dot 4 fluid is clear, pale yellow or crimson red. Dot 5.1 is clear, pale yellow, or blue. Dot 5 is purple or violet. Dot fluids are controlled by spec, mineral oils are not. This makes it a bit more difficult to tell.

    It’s entirely possible you used Dot 4. I’d check the bottle if you can. Mineral oil and dot fluid do not mix, this is the easiest way to tell. If you have some red fluid left, mix it with the mineral oil you have. If it mixes, good, if it doesnt, then remove the dot fluid from the brakes and flush it out with mineral oil. Mineral systems are not compatible with Dot systems and vice versa. Dot oil will degrade the seals in a mineral oil system.

    It’s worth noting that Shimano fluid is better than say, magura. 280deg C vs 120deg C boiling points. Run Shimano for the best performance and lifespan.

    1 user thanked author for this post.

    Matt Bingham

    Shit. Yeah no label on the bottle. Although I can’t see why I would have DOT fluid, as a plus, so I’m hopeful that it’s mineral. And I already put it in the brakes about a week ago, and they work well, and they mixed with the Shimano fluid already in there. I think I’ll flush regardless and get some Shimano.



    Definitely flush out the fluid and replace it, if you’re second guessing the bottle contents. Better to buy a $20 bottle of Shimano fluid than to end up replacing your brakes…

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