What brake fluid??

ragamuffin2812

Evening,

Was going to have a go at bleeding the hope mono minis tomorrow, just needed to know if I can use the usual car brake fluid ( dot 5.1 ) as I have loads of it lying around as I used to be a mechanic, or is the fluid bike specific?

Cheers

DHA987S

Use the car stuff, it's the same.

Halfrauds add a few quid on "bike" dot 5.1 compared to the car example. Cheeky bastards

supersonic

Dot 3, 4 or 5.1. Not 5!

ragamuffin2812

I thought as much, just wanted to be sure. Thanks.

Jamieg285

supersonic wrote:

Dot 3, 4 or 5.1. Not 5!

Can they be mixed, or should they be flushed if you're changing/not sure what's in it?

cooldad

They can be mixed.

veronese68

cooldad wrote:

They can be mixed.

Except for DOT5 which is the work of the devil. DOT5 is silicon brake fulid and is completely incompatible with anything else.
DOT5.1 is competition spec normal brake fluid and is very hygroscopic, but has the highest boiling point. DOT4 has a lower boiling point, but is less hygroscopic so doesn't need to be replaced as often. DOT3 has the lowest boiling point and is least hygroscopic.
Shimano mineral oil, I now know, is the same as LHM used in Citroens and such like, but with a different colour dye in it.

ragamuffin2812

Flush the system dude, brake fluid is hydroscopic, in short this means over time brake fluid absorbs water, mixing the fluids will result in new fluid being contaminated with old water absorbed stuff.

Just done mine and amazed at the difference it makes, plus the hopes I bought second hand must have never had a change as the fluid was black !!!!!

ragamuffin2812

Hahaha! Also what Veronese said!