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Stupid Question - I...
 

[Closed] Stupid Question - I have to know

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[#1081156]

I have Shimano disc brakes at the min - which use mineral oil versus DOT 4/5?
Is it possible to use mineral oil in brakes that use DOT4/5 & vice versa or am I going to have a lesson in why you can't.
I had to ask as it's been on my mind for some time.


 
Posted : 28/11/2009 2:17 am
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One degrades the seals in the other ... Buggered if i know what way round though!


 
Posted : 28/11/2009 5:52 am
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I think they both degrade the seals if in a system DESIGNED for the other fluid. Why would you want to use DOT anyway, unless you regularly cook your brakes mineral is fine and far easier to handle.


 
Posted : 28/11/2009 1:36 pm
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Dot will degrade the seals on mineral brakes, but i don't think mineral degrades dot seals. How could it? saying that i would stick to what the maker says.


 
Posted : 28/11/2009 1:42 pm
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DONT - well not without a head cam on the Black run


 
Posted : 28/11/2009 1:53 pm
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Mineral definitely degrades dot seals, short term will cause swelling(think diaphragms that look like elephant's ears, and sticking pistons at both ends), followed by fluid leaking out, and if left long enough, seals turning to an immovable glue like substance.Worth noting that some spray lubes likely to be used on lever pivots have a similar effect too.


 
Posted : 28/11/2009 7:22 pm
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Thanks for the feedback, I think I'll sleep a bit better at night now that I know.Cheers


 
Posted : 28/11/2009 8:29 pm
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Worth noting that some spray lubes likely to be used on lever pivots have a similar effect too

Didn't know that. Can you tell us which sprays to avoid?


 
Posted : 28/11/2009 9:09 pm