The reason you can't use Dot 5 with ABS systems is that we (did I mention
I'm an ABS systems engineer) use EPDM rubber in our seals. EPDM and
silicone don't get along at all. Dot 5's major pro's are it's almost zero
hydroscopic characteristic (won't absorb water) whereas Dot 3 and 4 are 5%
hydroscopic, and Dot 5 has a much higher boiling point which is why it is used
in race cars where they tend to do much more agressive braking. Also, Dot 3 and
Dot 4 are interchangable.
All in all, I'd say the moral of the story is, unless you're planning on doing
something
other than driving your car on the street, stick with good old Dot 3.
Seth
#1544
*********** REPLY SEPARATOR ***********
On 12/9/01, at 1:24 PM, Walter Coe wrote:
>
>About brake fluid:
>I disagree with what Seth said about the silicone brake fluid. If you put
>Dot 3 in a system made for Dot 4, then you will rot the seals out. But the
>presence of some Dot 3 or Dot 4 in a system made for that kind of fluid will
>not suddenly make silicone (Dot 5) fluid eat your seals if you add it to the
>system. A light residue of Dot 3 or Dot 4 will not harm anything when
>converting to Dot 5.
>
>Dot 5 is great for show cars that don't get used much. The zero moisture
>activity makes it great for cars that just sit. But for a heavily used car
>it isn't as good because it doesn't lubricate as well. It is also makes it
>very hard to get all the air out of the lines. And it can't be used in an
>ABS system.
>
>Walt Tampa, FL (#3633, but that's a DeLorean)
///
/// bricklin@autox.team.net mailing list
/// or try http://www.team.net/cgi-bin/majorcool
///
|