How to Set Up the Hydraulic Fan on Your Unidrill

How to Set Up the Hydraulic Fan on Your Unidrill

The hydraulic fan on your Unidrill leaves the factory ready to run, but every tractor is different. Getting the oil flow set correctly before you start protects the motor and the seals, and it only takes a few minutes. Our video below shows the whole process, and the key steps are written out underneath.

Step 1: Turn the tractor oil flow right down

Before you start the engine, turn the oil flow from your tractor spool right down. On a tractor with a screen, start at around 5%. Some tractors have a manual adjuster on the spool valve itself instead. It is always easier to start low and work up, and it saves problems later.

Step 2: Check your hoses

You need a large, free flow return line going back to the tractor with no restrictions, plus the main feed line from the spool. A restricted return is the most common cause of trouble, so check this first.

Step 3: Set the flow using the back pressure gauge

Start the engine and look at the small gauge on the return side of the hydraulic pump. It shows your back pressure. You want the needle sitting between the middle and three quarters of the way through the green. That tells you the motor is getting good flow and the oil is returning to the tractor freely.

Adjust the flow from the tractor screen or the manual valve until the needle sits in that range. Once it is set, you do not need to change the tractor flow again.

Step 4: Set your fan speed

From here, fan speed is controlled by the adjuster on the drill. Turn it up or down and the cab meter will show the actual fan speed. The fan speed will change, but the pressure gauge needle should stay where it is. If it does, the setup is right and you are not putting too much pressure through the motor. Getting the tractor flow set correctly first is critical.

Tractors with power beyond or load sensing

On some modern tractors, or tractors with power beyond, the valve block needs changing from a three way to a two way valve. To do this, screw the top valve in. That makes the other one redundant. Fan control is then handled from the tractor, because its self regulating hydraulics recognise when the fan has power, so the motor is not at risk.

Some tractors also use a load sensing line. In that case you will need to make up a load sensing line from the drill to the load sensing port on the back of the tractor. If you are in any doubt about which setup your tractor needs, speak to your tractor dealer, as they can advise.

Quick recap

• Set the tractor oil flow low before you start, around 5% on a screen.
• Make sure the free flow return line is unrestricted.
• Set the flow so the back pressure needle sits mid to three quarters green, then leave it.
• Adjust fan speed only on the drill adjuster.

Need help?

If you have any questions about setting up the fan on your Unidrill, give us a call.