Leak below seat – lifting arms?

In order to pin point a leak you have to first get the area clean and dry. A pressure washer is good for this but if you don’t have one some spray foam engine cleaner and a garden hose will work.  For smaller areas some mineral spirits on a rag will work too. Brake cleaner will work but it expensive and will take off the paint.

Once clean and dry you can operate the tractor and check the area every few minutes to see if you can find the leak. As a last resort you can get a fluorescent additive for the hydraulic fluid and then use a black light (UV) to see the trace.

You are probably correct about it leaking at the 3 point rocker shafts. There are seals in there but they are not very tight. The rocker shaft goes through the upper portion of the hydraulic tank and if you overfill the tank it will leak out at the rocker shaft.

Even a tank with the fluid at the proper level can flood that shaft if you are working with the front of the tractor higher than the back. I have this issue every winter when I am pushing snow piles up high.

The other thing that can cause the tank to “overfill” is if you have air getting into the hydraulic fluid. It will foam up and push out of the vent tube. To check this run your tractor for a while and then pull the fill plug and look inside with a flashlight.

These tractors are dead simple in design and easy to work on if you have a good parts diagram to follow. Some of the factory diagrams take some close study to understand how everything fits together.

There are several documents you can download on my website under the Jinma link on the home page. http://www.harnerfarm.net

Pictures are always helpful even for your own records for future use.

I had a huge leak show up in the middle of moving snow last winter. After 14 years a bolt on the 3 point control valve decided to come loose and it blew the gasket out. I would suggest taking some wrenches and make sure all the bolts in the area are good and snug. It is always a good idea to go over these tractors every now and again and check all the bolts that you can get to with a wrench. The Chinese lock washers are not the best and they do work loose. Wheels especially but loader frames are a close second.