Ask The Mechanic

Steve Thompson, Contributing Columnist

Q: I have a B8200E Kubota that has a hydraulic problem. The tractor has been resting for about two months, and now, the hydraulic lift won’t rise up. The tractor has a standard transmission. I checked the transmission oil on the dipstick under the seat, and it is milky. Does the oil on the dipstick under the seat supply the oil that the hydraulic lift uses? Several people have recommended I change the hydraulic filter. I could not find a hydraulic filter on this tractor. Can you help me with this problem?

A: The dipstick under the seat on this tractor does reflect the oil level for the hydraulic system. Since it is milky, that means moisture has contaminated the hydraulic oil. When moisture gets in hydraulic oil, it turns very milky and thick. More than likely, the reason the lift won’t work is because the filtering system is plugged, and the pump can’t draw any oil to pump. This tractor does not have an exposed hydraulic filter. You will find a screen filter with a very fine mesh inside the suction line that fits on the bottom of the tractor. You can find it by tracing the big line from the hydraulic pump down under the right side of the tractor. You will need a 26-mm socket, and the fitting will be very tight. Remove the fitting, and on the end, you will find a screen filter mounted on it. It will have a film over it, restricting any oil from the tractor to the hydraulic pump. Drain all the oil in the tractor at this opening, clean the screen, replace fitting and screen, and fill with new hydraulic oil. I bet your lift will work. Check the boot on your transmission shifter for holes or cracks. Many compact tractor manufacturers use the screen for a hydraulic filter.

Q: I have a BX23 Kubota that has a unique problem. It will not die. I have had lots of tractors that would not start, but my little BX23 did not die the other day. I turned the key off, but it kept running. I pulled all the fuses, and it kept running. I disconnected all the wiring harnesses, and it kept running. I didn’t want to turn off the fuel because I was afraid it would not start until I got all the air out of the system. I called my uncle, and he told me to take off the air inlet hose to the engine and put my hand over the opening to the engine, and it would die. He was right; it died instantly. Now, what should I do to fix this problem?

A: Today’s tractors die in many different ways. Some die electrically through a solenoid, and some die by pulling the throttle all the way back. Some solenoids stop the engine by extending at the pump; others die by retracting at the pump. Some can die by pulling a knob and releasing compression on the engine. However, your BX23 (and similar Kubota tractors) start and die by doing an electrical trick. Actually, applying voltage to the start/kill solenoid on your tractor is what makes it die. I get many questions about this particular start/stop circuit, because everyone is usually thinking there should be no voltage at the solenoid when the key is off rather than when the key is turned off. So, all the steps you did to kill the tractor were actually working against your ability to kill the tractor.

On your tractor, when you turn the key to off, the solenoid is energized and moves the linkage to kill the tractor. Then, a delay allows the solenoid through the tractor’s system to drop voltage, allowing the solenoid to return the injector pump back to run mode. When you return the key switch to start, the engine will run. More than likely, you have a bad solenoid that is not moving when you shut off the key. A quick voltage check will determine the problem before you start buying parts. By the way, your tractor will not die if the battery is low because it takes proper voltage to kill the tractor.

SAFETY TIP OF THE MONTH:

Rear tractor tires can be heavier than they appear, especially if they contain liquid ballast. When the wheel is removed, it can quickly fall on you, because the water runs to the top of the tire as it leans away from the tractor, increasing its leverage on you. Before you remove a rear tractor tire, roll the tire in order to place the valve core near the bottom, and push in the valve core to check for liquid in the tire. Be careful with this one. One note: Most tire repair shops repair the tire without removing the wheel from the tractor.

Write Steve Thompson at Ask The Mechanic, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email mechanic@progressivefarmer.com.

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