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what's the difference between the various brake fluids?
is it viscosity?
can i use either in a brake? obviously ill flush the old stuff out.
thanks.
Dot 5.1 and 4 are interchangeable.
Dot5.1
+ Higher Boiling Point
- More hygroscopic so absorbs water more as a result means more frequent bleeds
Dot4
-Lower Boiling point
+ Less hygroscopic
However on a bike you probably won't notice any of the above and just go for whatever is cheapest!
Dot 1,2,3,4 & 5.1 are interchangeable. Higher numbers are better and Dot 5.1 is best. Dot 5.1 has lower viscosity at low temperatures (for ABS etc...) and others have gradually increasing boiling points that correspond with the Dot No's i.e. higher number equals higher boiling point.
Dot 5 is a silicone based fluid and is NOT interchangeable with the others.
Check that your brake system doesn't use Mineral based fluids - these are very different to Dot fluids and they CANNOT be mixed together - even if you flush for days!!