Brake flushing

Taka Mizutani t44tqtro at
Tue Dec 13 07:53:15 EST 2005

DOT 5 is NOT a good idea- it is usually recommended only for use in cars
that rarely get
driven, due to the less corrosive nature of DOT 5 fluid. Collector cars that
get driven off the
trailer and displayed, stuff like that, from what I've been told.

If you're worried about water absorption and you don't mind the cost, get
something like Castrol SR-F (which I believe stands for "Silicon Racing
Fluid"), which is $80/L, but has excellent wet boiling properties- maybe
that is what you've used previously? That stuff is DOT 5.1, not DOT 5.

DOT 5 fluid is incompatible with any other fluid, so you need to completely
flush the whole system very thoroughly or use all new brake components- thus
the note about collector cars that mostly sit.

In a car like the Audi with single piston calipers and ready compatibility
with the Motive pressure bleeder, I'd just bleed every other year with a
couple liters of your favorite off-the-shelf fluid- I used Ate Super Blue
with good results.


On 12/13/05, Adam Gratz <adamgratz at> wrote:
> A note on brakes and Biennial flushing:
> I ran my BMW 2002tii for 11 years with silicon brake fluid (concept stolen
> from the motorcycle racer I used to work for) and *never flushed
> anything*.
> I understand that the reason systems need flushing is to remove the water
> that the petroleum based fluids naturally absorb. I flushed out the system
> with brake cleaner and then with the silicon fluid (not cheap) then bled
> it
> as usual. I really drove the holly hell out of tha car, and never heard
> any
> complaints from the brakes, no fade stick or otherwise. The injection
> pump,
> was another story....
> I'm tempted to do this with the 20v since the humidity is so great here in
> Hawaii.
> Thoughts?
> Dr.G

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