Brake fluid. Synthetic safe?

[COP TZR]

I'm about to install my brake system and new clutch master.  My pee cups say to use DOT4 brake fluid.  Everything I find in the stores is synthetic.  Is this ok to use, or should I just put DOT 3 in there?

[He Man]

synthetic is better as it will take more heat. just make sure its dot 3 or 4 or 5 POINT 1 (5.1)
I think some places market synthetic 3 as better than regular old dot 4.

[Major Slow]

Dot 4 is a spec that doesn't specify what is on the fluid except it can't contain silicon. http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?section=571.116.

The big difference between DOT 3, 4, and 5.1 is the biol temperatures.

To answer your question DOT 4 is DOT4 use any.

for those that point out AMSOIL is best, they do make a DOT 4 fluid.

[COP TZR]

I was just worried that I was going to have issues with the synthetic mixing with the residue from the old fluid remaining in the lines.  Something along the lines of like water & oil dont mix.

So the Valvoline DOT4 synthetic is good to go!  STP & Pennzoil also have.  Is one brand better than the other, or should I just buy whichever is cheaper?

[Howie]

All brake fluid is synthetic.  Use any DOT4 or DOT 5.1.  You can use DOT3, but the boiling point is pretty low.

[COP TZR]

All brake fluid is synthetic.  Use any DOT4 or DOT 5.1.  You can use DOT3, but the boiling point is pretty low.

Well that clears it up.  Thanks!