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Brake fluid - Dot 5...
 

[Closed] Brake fluid - Dot 5 and dot 5.1

Posts: 11
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[#6334808]

Anyone know if these are ok to mix? I've got to bleed a formula brake and they specify Dot 5.1 but I've got some dot 5 in the garage and was hoping I could use that.
Any idea if this will be ok or will I die?

Cheers y'all!


 
Posted : 12/07/2014 12:30 pm
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No, it's not.

DOT 5.1, like DOT 3 and DOT 4, is a polyethylene glycol-based fluid (contrasted with DOT 5 which is silicone-based). Polyethylene glycol fluids are hygroscopic and will absorb water from the atmosphere, which is necessary to prevent sheer and undiluted water in the braking system,[citation needed] which is very corrosive, also water droplets can freeze in the pipes, thus blocking the system.

http://en.wikipedia.org/wiki/DOT_5.1


 
Posted : 12/07/2014 12:32 pm
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Can't mix DOT 5 and DOT 5.1.

Can't mix DOT fluids and mineral oil.

Can mix DOT 4 and DOT 5.1.


 
Posted : 12/07/2014 12:32 pm
Posts: 11
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oh, shame. Off to the shop for me then! One of those jobs I really should have sorted in the week - I could be out riding now.

Cheers everyone!


 
Posted : 12/07/2014 12:35 pm