WCB elements (Water Cooled Brakes)are disc type, externally cooled units. They are designed to absorb and dissipate the thermal loads associated with the most severe clutch and brake applications. The WCB friction couple was developed specifically for continuous slip service and has a dynamic coefficient of friction that is greater than its static coefficient off riction.Pressurizing the cylinder causes the piston to clamp the friction disc between the water jackets.