Need to flush my brake fluid before my fall season next month. What do you guys recommend?

http://www.suncoastparts.com/product/RBF660.html

http://www.suncoastparts.com/product/CASTROLSRF.html

It's a DD street car with stock pads BTW. Thanks.

 

Stick with a street fluid. You will never be at risk of boiling the fluid on the street. You do not need a higher boiling point. By increasing the boiling point you also make the fluid more hygroscopic which means you will need to change the fluid more regularly.

 

She will be hitting the track this fall 1-2 times every month for the next 3 months. Thus thinking to flush the brake fluid now before hitting the track next month.

 

Makes perfect sense then and I apologize for incorrectly interpurting your post. In that case we have had great success with the Motul RBF600. Both are great fluids.

 

Thanks for your advice. Do you think 2 is enough to flush a 991 brake system?

 

That should do the trick, but get 3 just in case. It never hurts to have a little extra in your track box.

If you do the SRF 2 is plenty as those are full liters and not half liters like the Motul.

 

With that frequency of tracking, I'd do the Castrol SRF. You'll have to change it at best after a year but you won't boil it on the track.

 

That what i used to believe and then was educated on Castrol SRF (and a few other high performance racing brake fluids).... seems that its hygroscopic qualities are even better than street fluid along with the higher boiling points. needs to be changed less often due to its fluid performance qualities.

 

So the label claims. I still don't believe. The next time the lab that does all the DOT testing comes in to pick up brake fluid up I will ask him. I have had some lengthy conversions with him.

 

Brake fluid chemistry is complex to be sure. I have never seen any data that suggests that brake fluids with higher dry and wet boiling points are more or less hygroscopic because of the higher boiling points. Castro SRF is marketed as being less hygroscopic than "typical" brake fluids.

In my personal experience, I have found Castrol SRF to work better longer than any Motul product. More so than would seem to be indicated by the difference in wet boiling points.

 

i think your comments on this a while ago, made me re-think about my brake fluid budget and choises (and the large size of the container vs the small "other brands" vs cost).
Using SFR now in both my street car and the race car and seems to be better.
(vs the usual well known suspects)
good point about the wet boiling point, because if it had adsorbed any moisture from the air, boiling point would go down, not be higher.

 

I"d throw Endless RF-650 into the mix of this conversation. I switched to it from Motul 600 (not the 660 mentioned here) a couple of seasons ago and could not be happier. I have better pedal feel now and my bleed intervals are 4x what they were with the Motul. As a matter of fact I could probably go longer on the bleed process It just gets to the point where I feel I should do it on time vs. degraded pedal feel

 

There is no real reason your pedal "feel" would be any different with any brake fluid. this is a function of the bleed process. even used fluid will feel the same with the brake fluid doing what it does hygroscopically. its not until that water in the oil is turned to a gas, do you feel a "soft" pedal. (aka: boild brake fluid)

 

Endless 650 for me as well. Spec for Cup Cars. Superior performance than Motul 600 and the old Blue stuff. Only bleed when figure it's time to. Not because of soft pedal. Speed bleeders rock !

 

Endless RF-650 is supposed to have less compressibility than many (most?) other fluids.