The Motul RBF 600 Factory Line is a 500 mL bottle of 100% synthetic, polyglycol-based DOT 4 racing brake fluid, sold under part number 100949. The manufacturer designs it for hydraulically actuated brake and clutch circuits that require a non-silicone fluid. It is formulated for the heat of steel or carbon racing brakes, and it is also suitable for conventional steel-disc systems. Its headline figure is a 312°C (594°F) dry boiling point, which the manufacturer says exceeds the requirements of the standard, giving a firmer pedal when track sessions push the calipers hard.
The case for paying more than a standard DOT 3 or DOT 4 fill rests on boiling resistance during repeated hard stops, when vapor in the lines compresses and the pedal goes soft. Owners on user forums report that high-boiling DOT 4 fluids pull in moisture quickly, so the wet boiling point slips faster than the dry figure suggests, and frequent replacement is the practical answer. Published wet boiling values differ between sources, so confirm the current figure with the manufacturer before relying on it. Because the fluid is universal, verify that your car uses a DOT 3/4-class system, and never introduce silicone DOT 5 into the circuit. Searchers looking for RBF 600 Factory Line DOT 4 racing fluid, part 100949, high dry boiling point track brake fluid, or steel and carbon brake fluid for track days will find this matches that need.
Owners on user forums report that DOT 3, DOT 4, and DOT 5.1 fluids can be mixed with one another without problems. Silicone DOT 5 is the exception and should not be combined with any of them. Mixing is acceptable, but a full flush gives the cleanest result.
The manufacturer states it is suitable for conventional steel-disc brakes as well as racing setups. Forum members who run it on the street generally suggest changing it about every two years, and they add that humid climates shorten that interval.
No. Viper owners on user forums warn that the Motul DOT 5 product is a different fluid and should not be used in place of the RBF 600 DOT 4 formula.
Replacing this fluid is a moderate DIY job: it is a full bleed rather than a single-step fill, and it is manageable with basic hand tools, a clear hose, a catch container, a box-end wrench that fits your bleeder screws, and fresh fluid. Owners on user forums commonly describe the classic two-person method, with one person pumping the pedal and another opening and closing each caliper bleeder, and they stress keeping the master cylinder reservoir topped up so air does not enter the lines. If you use a pressure bleeder, keep the pressure low, since forum members report that excess pressure can blast fluid back out through the cap or bleeder seals. Work with the fluid in a ventilated area, and wipe up spills promptly because brake fluid damages paint.
