John Deere 650

[DRussell]

Some questions about a JD 650 tractor. This is one of the mini series.

The tractor has a loader and they are having trouble with the hydraulic valve. They are thinking about a new valve with joystick instead of two lever controls.

Is this closed or open center hydraulics?

Also, what is the bottom line coming out of the valve for? See pictures. The first picture shows the line coming out of the bottom of the valve directly under the painted number on the valve. The second picture shows that same line going into the side of the transmission on the left side.

 

[DRussell]

Picture showing the valve from lever end.

 

[Gene Davis (Ga)]

A joystick control works really nice when you get the hang of it. You will probably have to make a mounting pad for another type of valve. The hydraulics are open center and the line out the bottom is the return line to the transmission case/reservoir. For the record I have a 650 now also and I used an International Cub loader adapted to it for 6 years until I bought my loader/backhoe tractor.

 

[DRussell]

Thanks Gene, in addition to the bottom line, there are two other lines to the valve body. One is labeled in and the other is labeled out. Could that bottom line be a case drain?

 

[Mike M]

open center system. Valve will have a pressure in ,a return ,and a power beyond port. Not sure which one is which.They should have some sort of markings.

 

[Gene Davis (Ga)]

The loader I had was not a Deere loader but was an adapted International loader made for a Cub lowboy and I had to use a non John Deere hydraulic set up and routing of the loader lines. Later on when I installed a John Deere power steering kit with the priority valve for steering was when I installed the return line back to the transmission case fitting that came with the power steering kit. I don't know what the bottom line does or goes to as I didn't have that on mine.

 

[DRussell]

Lines run from under the seat on the front of the rockshaft housing up to the loader valve. Ports on the rockshaft housing are labeled IN and OUT. There are ports on the valve body also labeled IN and OUT.

A line runs from the OUT on rockshaft to IN on the valve. Another line runs from OUT on valve to IN on the rockshaft. Then there is the third line coming out of the bottom of the valve running back to the side of the transmission housing.

It makes sense to me that the IN/OUT lines are the flow of oil. What doesn't make sense is the line out of the bottom of the valve to the side of the transmission housing.

 

[Mike M]

Dad has a 750 and I installed the valve on it years ago. 650 is the same you put a small allen plug inside of one of the rockshaft housing ports. This sends the pressure oil up to the loader valve first. Then it comes out the loader valve power beyond port and goes back to the rockshaft so it can work. The return oil for the loader valve just returns back to the transmission housing.
You never said what sort of problem you are having with the valve ?

 

[DRussell]

The valve was rebuilt by someone else about a year ago and is now leaking pretty significantly. The tractor isn't mine, I was asked my opinion about it and my suggestion was to change it to a joystick style valve rather than fix it again. The price to rebuild it a year ago was more than a new valve.

I wasn't sure about whether it was open or closed center and why it has three lines to the valve.

The valve has two ports clearly marked IN and OUT and those two lines go to the rockshaft housing. The bottom line is not marked at all.

Are you saying the OUT port on the valve is actually the power beyond port?