Most liked posts in thread: Brake fluid comparison thread.

Since you mention low viscosity fluids, ATE makes a 700 viscosity DOT4 compared to the usual 1400 viscosity,
that's supposed to be more responsive in modern ABS systems. I have no idea what difference this actually makes
in practice*.

ATE SL.6 ($12/33oz = .36/oz) 509-338 = 171

* Einstein -
In theory, theory and practice are the same. In practice, they are not.

 

Yes, the higher BP fluids are more hydroscopic and require more frequent changes. ATE is less so, and is fine for a street car. Motul 600/660 is awesome--it's what I use on the track--buts it's overkill for the street, it's expensive, and needs to be changed every few months.

You do not want to use a 5.1, motul or any other. It's silicone based, a no-no in our cars.

 

In run Motul Rbf 600 and change it twice year once is the fall and before the Dragon.

 

That's about right. I bleed so much I'm constantly turning the fluid over.



ATE you can easily go a year. Don't like it on the track though.

 

"DOT 5 is silicone-based brake fluid and is used in most new cars today. DOT 5 is expensive, but it has a dry boiling point of 356 degrees. Newer brake rotors tend to be smaller and thinner, which means they disperse heat a lot less efficiently. Also, DOT 5 does not absorb any moisture. DOT 5 will not harm painted surfaces and acts as a weather barrier for your brake system, preventing rust. DOT 5 can be used as an upgrade or replacement for both DOT 3 and 4, but should not be mixed with any of the other fluids. The procedures to convert your DOT 3 or 4 systems to the silicone-based DOT 5 are similar to the Dot 4 conversion procedure mentioned above. Silicone-based brake systems tend to be more difficult to bleed, but once this is accomplished, a DOT 5-filled system will resist rust better and last longer than the other formulations. Silicone brake fluid is also much lighter in cold temperatures, only about 900 weight at -40 F.

A new formulation has recently been developed called DOT 5.1. This fluid is identical to DOT 5 silicone in both boiling point and viscosity; however, it is compatible in the poly-glycol based systems and anti-lock brakes as well. DOT 5.1 can be used in place of either of the poly-glycol-based fluids even though it has half the viscosity of DOT 3 or DOT 4 fluid. In fact, DOT 5.1 can be intermixed with the other non-silicone based fluids."

Copied and pasted. The 5.1 actually looks ok.

 

The amount of water pickup is dependent on the glycol content. They are obviously adding other things in along with glycol to influence wet/dry boiling points, but at the end of the day it depends on the glycol.