i'm going to install Challenge SS lines that i got - so i thought perhaps to use dot 5.1 or Motul RBF600.

my concern is its longevity in hot and humid climate (think Florida or 7-8 months similiar to NYC's summer).

i drive ~1,000km every month and my car i used mostly on weekends and mostly for spirited driving and sometimes x-cross - so reducing brakes fade feeling is important to me.

but i don't want to replace brake flueid every 3 months....

so what do you think?
will it last a year whithout significant degrading?

Thx,
Gennady

 

I'd start out with an inexpensive DOT-4 and see if boiling is an issue on track. If boiling is a problem, you can upgrade to DOT-5.1 without worrying about DOT-4 and 5.1 mixing together a little.

Spirited driving and the occasional autocross shouldn't necessitate more than an annual flush and bleed in your conditions.

http://www.stoptech.com/tech_info/wp...fluid_1a.shtml

 

i already have dot4 refreshed 6 months ago.

so i understand that dot4 and dot5 absorbe humidity in a similar rate?

so if d0t4 worked OK for me for 1 year than dot5.1 should last the same?

 

I think you'll be able to go a year on a fill given your conditions. Here's a cheap way to monitor the health of your fluid.

http://phoenixsystem.com/products_by_type/...strip/index.htm

 

A brake ducting setup I did gave fade free performance over multiple track sessions over the course of a >1year tracking & daily driving in >90% humidity & high track temperatures.
I hope this article I wrote is helpful
http://www.tractioncircle.com/index.php?op...id=45&Itemid=73

 

eventually i put Motul RBF600.
pedal feel is light years better !!!!

frankly this also might be related to the way they bled the system - they used some vacuum orerated device which sucks the fluid.
this is instead of usual "mump the pedal" way which i suspect is less reliable.

anyway - i'm extremely happy now - finally S got brakes that it [almost] deserves.
imrovements always are welcome - but now it's really OK.