Wet Brake Systems

Construction equipment, farm equipment, forklifts, heavy duty trucks, and mining equipment have been utilizing wet brake systems for years. Wet brakes are a system where the braking surfaces are operated, lubricated, and cooled with oil. The advantages of this system are the brakes are not exposed to dirt, water, or other contaminates, they are cooled during braking operations to prevent warping and are lubricated to reduce wear. If well maintained and not damaged, they can last the life of the equipment without ever being changed.

There are two types of systems utilized,

1. a common sump shared with transmissions and hydraulics are commonly used in tractors, and
2. a closed system that uses its own hydraulic fluid is common on large trucks used in mining.

The basics are the same for both systems, there are several discs mounted inside the differential and spacers attached to the axels. Usually hydraulic pressure holds a spring-loaded pad open so the discs and spacers can spin freely, when the brake pedal is applied the hydraulic pressure is released and the pad presses the discs and spacers together and stopping the rotation. This also works as a parking brake when the unit is shut down. There are alternate designs where hydraulic pressure on the pad presses the discs and spacers together.

These systems are superior to the disc and pads on personal vehicles as they do not generate as much heat, there are multiple surfaces making contact, and they are not exposed to contaminates.

SWEPCO 709 Universal Tractor Transmission/Hydraulic Oil and SWEPCO 714 Heavy Duty TO-4/C4 Transmission Fluid both have the necessary additives to reduce brake chatter and the friction properties to allow the discs and spacer to stop the vehicle without slippage. The 709 and 714 are compatible with the composite materials used in the brake discs and spacers. The lifts on some construction equipment use the same type of system to stop or hold a load at a certain level.

SWEPCO 709 and 714 rapidly separate water for easy removal. Water in the fluid can cause damage and corrosion to the components.

“To keep it running…!”

Source: SWEPCO^®