mixing brake fluid

twain

Retrobike Rider
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have a shimano brake M755 - it looks to have non shimano fluid in it, but i need to top it up. can i put shimano fluid in (essentially mixing it)...???

bought the brake second had so dont know what fluid is already in it..
 
well i think i drained it....wasn't sure how to do that properly, so i just pushed through shimano fluid until it was all nice and pink in the reservoir and just worked out all the bubbles.....
the previous fluid was yellowish....
 
Yellowish sounds like dot fluid. Dont run them too hard for a little while and see if any leaks develop or if the pistons seize up.
 
i'm going out for a retrobike ride tomorrow hopefully, so we'll see how it all holds up!
 
shimano mineral oil is pink/red because of the dye the put in it

dot brake fluid will **** the seals

the colour doesn't really tell you much about what type of fluid is in the system
 
well the brake was working ok before i bled it (i.e. it wasn't awful, just a little too much movement on the lever before it bit) and the reservoir was about half - 2/3rds full when i opened it up, so hopefully that was the reason.

i aint fettling with it anymore as i'm due out in about an hour and a bit :? but a quick test with the pads and brake insert in tells me its been bled ok for now.....
 
magura and shimano * use mineral oil, dyed blue and pink respsectively, all other makes use DOT i.e. car brake fluid.

it is commonly stated that using the incorrect fluid will damage the seals but i have yet to hear of anyone doing, either it does not or nobody has tried it, or they have and did not post about the result.

I am only aware of those 2 makes, but feel free to add to the list.
 
I asked about this a little while back. You can use magura mineral oil in a shimano system, but apparently you cant mix them as the fluids are a slighly different weight and can separate. Just dont use dot fluid in a mineral system or vice versa and you should be sound.
 
Ive seen plenty of ruined shimano brakes where dot was used instead of mineral oil. shima oil fades to a colour resembling dot oil over time. If its had dot in it will flood out of the pistons. Tektro oil is fine too.
 
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