John Deere 790 - Lift Issues

[fatboy95]

Hello, I have a John Deere 790 that the bucket lift that bleeds down after being left up. I had all 4 cylinders rebuilt in hopes this would solve the issue but it hasn't. I am also assuming he actually rebuilt them since it is falling at the same rate before. There are no leaks anywhere on my system. I change my fluids annually, my tractor is used on deer lease and some around my house so not abused at all.

What would be best way to figure out what is causing this issue?

Thank you.

 

[dfkrug]

If no visible fluid leaking, it is the valve.

You don't say how fast your loader bleeds down. If you can not see it moving, then it is OK.

 

[fatboy95]

If i sit in the bucket it drops even faster. I don't feel like it has the full lifting capacity either. Seems extremely weak.

 

[dfkrug]

You could also have an internally-leaking relief valve. Some of those older gear tractors only have suction filtration.

A pressure test is called for. If you don't want to do that, you can check to see if another function seems to have the usual force. Does the 3pt lift also seem weak?

A worn-out implement pump or malfunctioning RV would explain low pressure.

 

[fatboy95]

3 point holds just fine. I can leave my tiller on and it never drifts. I will do what i need to figure this out but not sure where to start at this point after spending a ton just to have seals installed on all four cylinders for the bucket.

 

[dfkrug]

A pressure test setup is not expensive. You need a 3000psi gauge and some adapters to connect to one of your loader hoses.

 

[fatboy95]

I have a gauge. I will start checking them.

 

[hodge]

Does the bucket roll down also, or is it just the loader arms? Your loader valve is the next place to look, I suspect.

 

[fatboy95]

Yes both drop.