Motul’s RBF600 racing brake fluid boils at 594 deg F dry, 420 deg F wet. It is a glycol-based fluid and meets DOT 4 standards. It is compatible with all vehicles that use DOT 3 or DOT 4 fluid.
Is RBF600 right for you?
We know it’s difficult to choose parts for your car sometimes, so we thought we’d make it easier by offering a concise selection guide for Motul’s brake fluid products.
If you Ride your Bike aggressively on the street or do track days occasionally, Motul’s RBF600 is the fluid for you. It will last at least a year under street driving conditions before needing to be flushed, and has extremely high dry and wet boiling points – much higher than DOT 5.1.
The Details on Motul’s RBF600 Brake Fluid
Motul’s RBF600 is an excellent balance between extreme temperature resistance and fluid longevity. Because brake fluid absorbs water over time, and higher temperature resistant fluid absorbs water quicker, it is difficult to find a brake fluid that resists very high temperatures and does not need to be flushed every few months. RBF600 bridges that gap – its dry boiling point is 594 deg F and its wet boiling point is 420 deg F, and it will keep at its dry boiling point for six to twelve months before it starts to fade towards the wet boiling point. For a fluid capable of resisting such extreme temperatures, this is outstanding longevity.
Dry and wet boiling points? That doesn’t even make sense!
In this case, consider dry versus wet as the amount of water something contains. Brake fluid is considered dry when it is pure glycol and uncontaminated by water. It is considered wet when it is contaiminated by a certain percentage of water – usually around 4%. This standard comes from a DOT study of the average amount of water absorbed by average brake fluids after one year.
By the way, some vendors claim that the high wet boiling point means the fluid performs better in rain – this is simply not true. Your brake system is a sealed unit and the external humidity has only a small contribution toward the fluid absorbing water. If your car is exposed to extreme humidity on a constant basis, it will make a difference over a long period of time, but not in an isolated situation wherein it might or might not be raining.
As such, when Motul brake fluid is brand new and in an unopened container, it is at its dry boiling point. After some time spent in your car’s brake lines, the fluid will begin to absorb water through miniscule leaks in the master cylinder, brake line fittings, and so forth, and when it reaches 4% water saturation it is at the wet boiling point.
We recommend flushing your brake fluid after every race weekend, as once the brake fluid reaches a certain water saturation the water will begin to boil separately, causing the lever to compress substantially more than normal. For more extreme fluids such as RBF600, it is best to change the fluid more frequently to keep the performance benefits of these high temperature fluids.