DOT 3&4 Brake Fluid?

[MachineJoe]

So I stop into my friends auto supply store and ask him for Dot4 and gives me Dot 3&4

Is this acceptable to use in our RT's?

[The Fabricator]

Yes.  4 has a higher wet boiling point than 3.  No harm filling a 3 system with 4.  Bottle contains 4 fluid, which works for old 3 systems.

[dirtrider]

10 hours ago, MachineJoe said:

So I stop into my friends auto supply store and ask him for Dot4 and gives me Dot 3&4

Is this acceptable to use in our RT's?

Morning Machine Joe

 

Yes, you are good-to-go with that fluid. Dot 4 can be mixed with, or used in place of DOT 3, but not the other way around as DOT 3 should not be used in place of DOT 4.

 

If the brake fluid is specified as a DOT 3 & 4 that means it meets the DOT 4 specs (446°f dry boiling point). 

 

That is a sort of a marketing deal as it is basically a DOT 4 fluid that can be used in DOT 3 brake systems. 

[MachineJoe]

Thank you guys, I really do appreciate your input and experience.

[Dave_in_TX]

Not sure about previous models but BMW recommends low viscosity brake fluid for wetheads.

[dirtrider]

1 hour ago, Dave_in_TX said:

Not sure about previous models but BMW recommends low viscosity brake fluid for wetheads.

Morning Dave

 

Good point, we should have asked what motorcycle he is working with.

 

Neither the 1100 ABS-II or the 11500 I-ABS  require low viscosity DOT 4 brake fluid but BMW does currently sell low viscosity to use in those bikes. 

 

The newer BMW ABS bikes with the smaller ABS internal orifices' are speced to use low viscosity fluid though. Not sure if it makes a lot of difference unless ridden in very cold ambient temps then rider enters an  ABS  event.  

[MachineJoe]

Sorry for not mentioning that the bike I'm referring to is a 2017 1200RT and I don't ride below freezing temps