Mercury - Quicksilver DOT-4 Brake Fluid Marine & Powersports High-Temp Formula 8M0128415. Overview. Braking is one of those things you never want to question-whether you are easing a boat down a slick launch ramp, threading through heavy traffic on a motorcycle, or rolling down a steep trail on a side-by-side. You want to squeeze the lever or press the pedal and feel that steady, confident response every single time. That's why many riders, boaters, and powersports owners stick with Quicksilver