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How we reviewed this product: we studied the manufacturer's specifications, materials, included parts and warranty terms, read owner feedback where available, and compared it with similar products. We did not run our own lab tests.
Brake fluid is easy to forget, but it is what carries your foot's pressure to the brakes. When fluid gets too hot, it can boil and form vapor, and the pedal suddenly goes soft. Motul RBF 600 is a racing fluid made to resist exactly that.
Quick verdict
- Best for: track days, autocross, mountain driving and performance cars.
- Type: 100% synthetic DOT 4 (glycol-based).
- Strengths: very high dry and wet boiling points.
- Watch out for: for hard use, change it more often than standard fluid.
What RBF 600 is
RBF 600 is a fully synthetic, polyglycol-based DOT 4 fluid for brake and clutch systems. Motul lists a dry boiling point of about 312 °C (594 °F) and a wet boiling point of about 205 °C (401 °F). For comparison, the DOT 4 minimums are 230 °C dry and 155 °C wet. Motul says it exceeds DOT 3 and DOT 5.1 standards except for viscosity at -40 °C.
Dry vs wet boiling point, simply
The dry boiling point is for fresh fluid. Brake fluid absorbs moisture over time, and the wet boiling point shows performance after it has absorbed about 3% water. The wet number matters more for real-world use, and RBF 600's is high.
Pros and cons
Pros
- Very high boiling points for hard braking
- Fully synthetic DOT 4
- Works in brake and clutch hydraulics
- Trusted in motorsport
Cons
- More than most daily drivers need
- Should be changed often when used on track
- Must not be mixed with DOT 5 silicone or mineral (LHM) fluids
Who should buy it
Choose RBF 600 if you do track days, autocross or long mountain descents in a performance car, or if you have had a soft pedal after hard use. For a normal commuter car, a quality fluid of the type in your manual, changed on schedule, is enough. See our Prestone DOT 3 review for a daily-driver option.
FAQ
Can I use RBF 600 in a car that calls for DOT 3?
DOT 4 glycol fluids are generally compatible with DOT 3 systems, but always follow your vehicle maker's instructions, and flush the old fluid out fully.
How often should I change it?
Follow your manual for street use. For track use, many drivers bleed or flush before events, because heat cycles and moisture lower performance.
Before you buy brake fluid
- Check your owner's manual or the reservoir cap for the fluid type your vehicle needs (DOT 3, DOT 4 or DOT 5.1).
- Never use DOT 5 (silicone) fluid unless your system is specifically designed for it, and never mix it with glycol fluids.
- Only open a new, sealed bottle. Brake fluid absorbs moisture from the air once opened.
- Brake fluid damages paint. Wipe up spills right away.
Safety note: brakes are safety parts. If you are not sure how to do the job, have a qualified mechanic do it.