Racing Brake fluid for street use:
This Blog is not about brake fluid performance, there are tons of articles on the internet and opinions about this subject. What I see is people are using the right fluid for the wrong application. So just some facts to help you make an informed decision.
Often times at the store we have customers come in asking for racing brake fluid, they usually ask which one has the highest boil point or such and such race team uses this brand and they ask me what I recommend. I would reply “what are you using it for? Track days? Street/track days? Or street use? I usually get a weird look from them, “what does it matter, just give me the highest temp stuff “. Is the usual comment. Fact of the matter is, racing brake fluids need to be bled out as often as possible, and if you are not able to brake that bleed nipple after your track day and refresh your system with clean fluid, racing brake fluid may not be the best for your application.
Racing Brake fluid is Hygroscopic, this means that the brake fluid is designed to absorb water and moisture when exposed to the atmosphere. The braking system is in theory a sealed system, however the fluid reservoir cap and the microscopic pores in the brake lines and seals allow exposure to the atmosphere, after a year of use, the brake fluid will typically have absorbed up to 2% of its volume in water, and if you don’t bleed it out and put fresh fluid in, every time your brake system goes through a heat cycle (get super-hot and then cool down) the fluid would have absorbed that moisture from condensation,
Which Brake fluid is best for you?
My suggestion is if you are only going to bleed one or two time a season, then go with a Motul DOT 5.1 it has high enough wet boil point, it will surpass the allowable volume of moisture per DOT standards, and is able to cycle well in your ABS system at below -40 deg c. So, a great all-around fluid without having to bleed at the end of each session.
For those who are handy and don’t mind spending the time to bleed the system, Motul RBF 600 is a great product. With a high Wet boil point and good pedal feel.
For full out racing, meaning race car up in the air after each practice or qualifying session, wheels off, bleed and top up, (yes, every session!) we prefer the endless RF-650 and Castrol SRF, Solid pedal feel and high Dry boil point, these are my go-to depending if we are in an endurance or sprint race.
Happy motoring!