3-Point Hitch Jinma 3 point hitch problem

[Dickinson]

OK, now we're getting somewhere. So the problem is with how the FEL valve is plumbed.

The "normal" Jinma way of plumbing that valve is that the pump connects to the input, and the output of the valve goes to the input of the 3PH. When the valve isn't doing anything the fluid flows straight through the valve, and the 3ph works like the valve isn't there. If you were to lift the 3PH and the loader at the same time you could damage something, but I've had my tractor for ten years and haven't done that.

The "normal" everybody-but-Jinma way of plumbing that valve is to enable the power-beyond port on the valve. Pump goes to the input, and there are two outputs -- "unused" hydraulic fluid (ie at pump pressure) comes out of the power-beyond, and "used" fluid (at low pressure) comes out of the output. The power-beyond goes to the 3ph, and the output goes to the hydraulic tank (under the seat). The reason Jinmas aren't normally plumbed this way is that most don't have an opening on the tank to receive the "used" hydraulic fluid (because the FEL wasn't contemplated in the original design).

The first question is whether your valve has power-beyond enabled. If it does, you'll have an odd number of hoses -- input, output, power beyond, and two for each cylinder controlled. If there is no power-beyond you'll have an even number of hoses. The next question is to identify all of the hoses, and make sure they're going where they should be going. Post back and I'll help with that.

There are 7 hoses coming off the FEL control. The top hose is from the pump. The next 4 are for the front end loader. The two coming off the bottom feed the tank reservoir and the other into the 3 pt hitch control valve...which is not enough pressure to operate the 3 pt piston.

 

[quicksandfarmer]

OK, so you're set up for power beyond. Either the valve isn't set up right, the hoses are switched, or the valve isn't working.

I'm not familiar with that particular valve, your best bet is to see if you can find a manual for it. You want to see how to set it up for open center, power beyond. You want the power beyond port connected to the 3PH, and the return to tank going to the tank. Valves usually can be configured for a number of different setups, for power beyond there is usually an adapter that needs to be screwed into the power beyond port, check the manual and make sure it's there.

Here's a general description of how it's supposed to work, to aid in diagnosis. Your tractor has a constant volume/ variable pressure hydraulic pump. That means the pump moves the same amount of hydraulic fluid at all times. When there is no hydraulic work to be done the pressure is zero, the fluid moves without opposition. When there is work to be done the pressure increases to what is necessary to do the work at hand. When nothing is happening and the pressure is low, the fluid flows from the pump to the FEL valve, and out the power-beyond port to the 3PH, and from the 3PH to the tank, where it flows back to the pump. When you push on the FEL valve fluid flows into one side of one of the cylinders, and an equivalent volume flows out of the other side, and the flow of fluid is maintained. However, the fluid that comes out doesn't go out the power-beyond port, it goes out the return-to-tank to the tank. This keeps you from using more than one hydraulic device at a time. As you're doing this the pressure between the pump and the FEL valve rises to what is needed to lift the load, the pressure at the power-beyond and the return-to-tank remains zero (or close to). When you use the 3PH, the fluid flows from the pump to the FEL valve, out the power-beyond and to the 3PH. If you raise the hitch, the pressure will rise as needed to do the work, at the pump, the FEL valve, the power beyond, and the input to the 3PH.

If the return-to-tank and power-beyond hoses are switched, your 3PH isn't going to work. If the power beyond adapter is missing from your valve, the fluid will just flow to the tank and bypass the 3PH. I would start with the manual, but you could also get a pressure gauge and see if you're getting pressure everywhere you expect it (and nowhere you don't).

 

[Leejohn]

Do you understand now how to hook it up with or without the PB port?

 

[Dickinson]

Do you understand now how to hook it up with or without the PB port?

Yes you and quicksandfarmer have been a big help. I believe he is correct in one of his assumptions of the valve possibly not working properly or possibly I need a PB adapter to screw into the port. Does the adapter actually channel the flow of the hydraulic oil differently than what the normal opening of the port would supply? Currently I can screw the 3 pt hitch hydraulic supply hose into any available port without an adapter....unless the adapter inserts deeper and channels flow that would not be at HP without it installed? This is also for you quicksand farmer.

thanks for both of your help!

 

[quicksandfarmer]

Does the adapter actually channel the flow of the hydraulic oil differently than what the normal opening of the port would supply?

Yes.

Without the PB adapter, all of the hydraulic fluid leaving the valve goes out the return-to-tank, whether or not the valve is being used. No fluid would reach the 3PH.

But you should see if you can find a manual for the valve online, that will tell you what's going on.

 

[Dickinson]

Yes.

Without the PB adapter, all of the hydraulic fluid leaving the valve goes out the return-to-tank, whether or not the valve is being used. No fluid would reach the 3PH.

But you should see if you can find a manual for the valve online, that will tell you what's going on.

Ok thanks!
I've been looking non stop...still looking. I know from the numbers that the Walvoil valve was made in 2006 but still can't match the exact model. Will keep looking.