What Is A Wet Kit On A Semi Truck?

Semi trucks, or bobtails depending on load, can move or transport all sorts of materials, from full-size cars to trash and waste. These vehicles can utilize hydraulic-based equipment to get the job done, whether that means a concrete mixer or a rig to transport other vehicles. And while Tesla is trying to overcome road bumps for its electric semi, sometimes a good old fashioned diesel engine semi has its perks. One of those benefits is the ability to use a wet kit or a wet line kit. 

A wet kit is an option available for those looking to gear up a semi truck with impressive hydraulic power. While some basic equipment can run on its own, higher-powered jobs require this additive upgrade. That said, it's not just the wet kit that allows for the power boost, it's a part of a system that will also require the installation of a power take off (PTO) and a hydraulic reservoir for the vehicle. Thankfully, wet kits are available with PTOs, and, alongside the hydraulic reservoir, are the basis for the vast majority of semi accessories and special equipment.

A wet kit for a semi truck works to help power additional equipment through the vehicle's engine. This all starts with the transmission, allowing gears to turn inside the PTO shaft. This creates a hydraulic system, which is when fluid and pressure is used to transfer force. That force makes additional gears rotate within the pump, creating suction from an oil reservoir to a motor or relief valve.

While this is happening, heat is being generated by the process, affecting the oil. Because of this, these wet kit systems typically involve some form of heat dissipation or cooling. Often some form of a heat exchanger and filter recycles the hot, used oil so that it can continue to be used to create suction. That suction is the force that powers hydraulic-dependent equipment.

While wet kits are something that's installed aftermarket, it does require a certified installation. As such, you definitely don't want to try equipping your semi with one without the proper knowledge or expertise.