Help with 3 point hydraulic lift on JD 790

[Fast Eddie]

This is my first tractor, which I bought about 3 weeks ago. So I'm basically totally ignorant. Today tried to connect my new 5 ft box blade to the 3 pt hitch and can't get the hitch arms to go down. I have the 790 manual but it simply says to use the raise/lower leaver on the right side of the operators seat. This doesn't do much. It does raise the lift very slightly after I stand on it, but it needs to go up/down much more.

The FEL works great so the hydraulics must be ok. Just can't get the rear thing to go up & down.

Appreciate any words of wisdom.
Eddie

 

[rdbrumfield]

Look by or behind the seat for a knob to turn. It might be yellow, turn it to the left to open a valve. What it does is slow the oil down so when you have a heavy emplement on it won't slam to the ground when you drop the lever.
you probably have it as high as it will go, that is why you don't get any up with it.

 

[6sunset6]

There should be a valve to control the speed. usually it's a handle wheel sticks out forward under the seat. If it is closed that would do it. open it

 

[kennyd]

Under your seat, there is a "rate of drop" knob for adjusting how fast the 3PH drops, it is probably closed. You will have to adjust it depending on the weight of the implement that is attached. If nothing is attached, then it needs to be all the way open.

 

[Fast Eddie]

Thanks everyone. The hydraulic oil flow knob is at the drivers feet just below the seat. I have it set mid-way between open and closed.

Does the PTO drive have to be turning? It just seems like there is something that I'm not doing.

Eddie

 

[RobS]

Yeah, what everyone else said about the knob under the seat though I thought it only affected the rate of drop. Wait 'til someone else (youngun) adjusts that knob without you're knowing it. It'll throw you (how do I know that?).

Let us know if that fixes the problem and good luck with your new 790. They're great tractors!

 

[kennyd]

Thanks everyone. The hydraulic oil flow knob is at the drivers feet just below the seat. I have it set mid-way between open and closed.

Does the PTO drive have to be turning? It just seems like there is something that I'm not doing.

Eddie

1/2 way is probably not enough with no weight on the 3PH arms. The PTO is a completely separate system, not related to the 3PH drop at all.

 

[RobS]

Ah, I get it now, you have nothing on the tph yet. Try standing on the lift arms, your weight should lower them if you have the knob open even a little bit.

 

[Fast Eddie]

Everybody,

Many thanks. I just discovered the problem. I'm almost ashamed to tell you guys what it is. Anyway, there is a black nylon strap holding the horizontal arms under tension. When I released the tension it worked as it should. I wondered what those things were.

Amazing to get 7 responses so quick. Great Forum.

Eddie

 

[hosejockey2002]

Hey, everyone's a newbie once. When I got my first tractor, I couldn't even describe to anyone what a 3-point hitch even was. Before I sold my last tractor, I tore apart and rebuilt the 3-point lift cylinder. You'll know your way around your tractor blindfolded in no time.

 

[RobS]

Gald to hear it was such a minor problem. Happy tractorin'!

 

[dirt ditch]

Hey, Nobody's perfect. Ill tell on myself. A couple months ago when I got my new 790, the 3pt worked fine with nothing on it. My wife helped me fill the ballast box with wheel weights and railroad spikes. That made the box around 800lbs. I started the tractor, picked up the box then drove around to settle the spikes. After backing up on the concrete I pushed the 3pt lever all the way forward. BAM! The box slammed the cement shaking the ground. My wife, who was standing about 8 feet behind the box, let me know I had scared the he** out of her and wanted to know what I was thinking. I was as stunned as she was. After parking the tractor was able to lower the 3pt slower by moving the lever a little at a time. That night I found the rate of drop knob in the owners manual. The rate of drop knob was all the way open. Which still did not help with the wife after I told her what I found in the manual. She has calmed down since then.

 

[RoyJackson]

OK...now my 790 3PH story...

I normally leave my loader off during the summer months unless I have a task for it.
I also bought a used ballast box for the tractor a couple years ago.

Well, had a task for the loader so I wheeled the ballast box (which was on a dolly in front of the loader) over and rigged it to the 3PH. Now, time to turn the machine around and install the loader.
Of course, when I pulled the lever, the ballast box (with about 500 lbs of sand in it) didn't lift. The front end of the 790 sure did though!!! Quite fast too!

Learned a lesson that day, let me tell you!!