A Third Function Valve is a hydraulic control valve that’s installed on your machine in order to add an additional hydraulic function. It’s often called a Third Function as it’s used to control an additional third hydraulic cylinder, the first two cylinders being on a front-end loader (Tilt/Curl). A hydraulic control valve allows fluid to flow in and out of cylinders or hydraulic motors to extend/retract them with the push of a button or moving a handle.
Most commonly these Third Function Valves are installed downstream from a loader valve via the power beyond port, and can be used for a wide range of implements such as:
- Snowplow tilt
- Snow blower
A common configuration of third function valve setups is shown below. They are typically connected to the power beyond of your loader valve, or they can be connected directly to your hydraulic pump.
We sell Third Function Kits that can be installed onto any machine. If you have a Kubota Tractor, we may have a machine specific kit created that will be everything you’ll need to install a third function. If you don’t have a Kubota Machine, or your machine isn’t listed, our Universal Third Function Kit will work great.
Third Function Valve Vs. Diverter Valve
An alternative to installing another hydraulic control valve (Third Function Falve), is to install a diverter valve. These valves divert the flow of fluid from one hydraulic cylinder to another, either manually or electronically. Another way to think of this is to imagine a tractor with a front-end loader that you want to install a grapple. You could remove the hydraulic lines from the tilt circuit of your loader and attach them to your grapple every time you wanted to open and close your grapple, however this doesn’t make much sense. Alternatively, you could install a diverter valve in-line with your tilt function. When you activate that diverter, the flow of fluid would divert away from your tilt function, and go to your grapple. See the illustration below.
What’s the benefit of a Third Function Valve over a diverter?
Diverter valves must divert fluid away from another hydraulic implement, in order to provide fluid to the new implement. However, with a true third function, you are installing a new control valve which can be used in conjunction with any of your other hydraulic implements.