We run good race brake fluid, such as wilwood. If you are on asphalt and you run hard standard fluid will not take the heat, brake fade! Rear end fluid, make sure its synthetic, we run red line shockproof lightweight. Lots of heat in these locked gears. Cluth does not matter, you are only pushing the slave in and out. DO NOT RUN CHEAP FLUID, these components were designed for street use, not race applications subject to heat and abuse.