John Deere 790 front loader problem

[conesville]

I have a John Deere 2007 790 with a John Deere 300 cp loader 61" and all of a sudden the loader will not tilt more than an inch. The transmission and the power steering works and the raising of the bucket works. The fluid reads full and no signs of leaks. I tried removing and putting hoses back but still no change. The selector switch is not locked for any movement either. Any suggestions on what else to check?

 

[TBN Support]

Welcome to the forum.

That sounds like a problem! I'm going to move your thread on over to the John Deere section to see if we can find you some advice.

 

[zzvyb6]

One of the bucket curl lines may be blocked. Failed hose, connector not fully inserted into the coupling, bent tube. Try switching the lift and curl circuit hose lines to see if the problem moves with the change. If you've now lost lift, then the problem is in the tractor lines. If bucket curl is still a problem, its in the loader. By any chance is the tractor parked outside and ice has formed in the hoses somewhere ?

I suppose you could just open the lines by removing the connector and streaming some oil into a bucket to see if there is flow.

 

[conesville]

Thanks for the reply.
I already disconnected and put back the quick connect on the selector control side. I do not see any bent lines. I will try to switch the hoses to see if the problem follows the hoses. But if it does could maybe the selector switch have a problem in it self that it is working only in the one direction? Do you know if those selector switches are made in a way that it is even possible to fail in one direction. It is not in any of the locked positions.
What could actually break down and the loader itself? It is greased! The piston maybe? Odd that it moves only by about an inch or so!

 

[conesville]

Welcome to the forum. That sounds like a problem! I'm going to move your thread on over to the John Deere section to see if we can find you some advice.

Thanks Catherine I am new to site. How do I even select a forum to write into it. I only was able to write the original in my profile page., I looked everywhere on site and nowhere do I see where to select and write into the forums .

 

[pmsmechanic]

I just want to see the eventual solution to this problem.

 

[sixdogs]

I have a 790 TLB and there is a "lockout" lever on mine over by my right knee. if you bump it or knock it off just a little, it locks a portion of the loader function. I recall it prevented tipping the bucket more than an inch or so. Mine looked OK but it was locked just a little bit. It's worth a look and I hope this isn't what you mean by "selector" switch.

 

[Zebrafive]

Do either of your hoses have an adapter between the hose and coupler? Normally you only see this adapter on the boom/lift cylinder hose for lowering the boom. The adapter is used to house an orifice to slow the lowering rate. It could have been installed on the wrong hose and if so it could be plugged.
I would do as zzvyb6 suggests; swap the bucket hoses with the lift hoses at the quick couplers.

 

[conesville]

Six dogs the lockout on the selector was the1st thing I checked and that does not seam to be the problem.

 

[conesville]

Do either of your hoses have an adapter between the hose and coupler? Normally you only see this adapter on the boom/lift cylinder hose for lowering the boom. The adapter is used to house an orifice to slow the lowering rate. It could have been installed on the wrong hose and if so it could be plugged. I would do as zzvyb6 suggests; swap the bucket hoses with the lift hoses at the quick couplers.

Zebrafive. Neither of the hoses have an adapter that I see. I do see a dial on the tractor that states turn to slow down. I thought that was for the rear ptu. I already tried to turn it and does not seam to work anything.

 

[sixdogs]

Six dogs the lockout on the selector was the1st thing I checked and that does not seam to be the problem.

When I had my problem I had to fiddle with the thing because what I thought was the center position really wasn't. Before you tear into things again, try a few minutes with that selector. Mine acted just like yours.

 

[conesville]

When I had my problem I had to fiddle with the thing because what I thought was the center position really wasn't. Before you tear into things again, try a few minutes with that selector. Mine acted just like yours.

Next time I am out at my place I will give it a try again. But I did that already 3 times. Then I am going to switch hoses to see if that helps.,Hopefully the actual selector valve is not bad itself.

 

[sixdogs]

Is this fixed yet?

 

[conesville]

Is this fixed yet?

I switched the hoses for the tilt and the lift and the bucket tilted and then I switched them back.
Has to be problem in selector switch. Went down to tractor shop and he said that sometimes on the switch it needs to get taken apart and freed up because moisture can get inside it if not used for months at a time. I do not see how I been using it that way for 6 yrs , especially since I was working with it for a few hours then it jammed up. The odd part is that it tilts about 2 inches and stops as if there was a limit set on switch. This happened after using new tooth attachment on bucket for 2nd time. Maybe worked tilt too hard and blown something inside switch? Bringing it to shop this week. Will let u know outcome.

 

[sixdogs]

Before you take it there maybe try something that may have worked for me. I'm not exactly sure because I did a few things at the same time. By selector switch I mean that thing by your right leg/knee that locks the bucket from dumping or the arms from raising or lowering.

On my selector switch I sprayed JD lube and then repeatedly worked the switch in all directions. Then I sprayed oil on it again and kept moving it around. The next time I tried, it worked so I'm not exactly sure what happened.

 

[zionview]

I had the same problem with my Kubota. Switched the hoses and got the opposite: boom would not raise and lower, bucket would curl normally. In my case, it was a worn quick connector, I replaced it, and haven't had any problems since. I hope your JD is something that simple.

 

[JimRB]

That knob you were turning was probably for the drop rate for the three point hitch.Put a heavy implement on the three point hitch and it may drop like a rock. Put a light implement on and it may float down. Think another way. Put your 50 gallon sprayer on the 3 poiunt hitch and raise and lower it. It may go down slow. Put 50 gallons in the sprayer and it may drop faster. Of course it depends on where the knob is as to how sensitive it will be to load. I have 150 pound implements without water or without seed or fertilzer that weigh a lot more when I am spraying weed killer, spreading fertilizer or seed. 500 pounds heavier when teh spreader is loaded up.

You adjust the speed of the PTO with the engine throttle.

 

[conesville]

I had it fixed. The 1 quick couplings from the selector switch female side needed to be changed they said. So they changed them all and Between to go over whole machine since it was there. Changed 2 grease fittings and tightened machine up a bit and greased up and etc cost me $850 plus another $150 for pick up and drop off.

 

[Jnf]

Has anyone tried to install jd model 67 loader on a john deere 790? Does anyone know what the mesurementts are? This one came off a john deere 750. I am new to site, if this is in wrong place please move it to proper place. Thanks

 

[pmsmechanic]

Has anyone tried to install jd model 67 loader on a john deere 790? Does anyone know what the mesurementts are? This one came off a john deere 750. I am new to site, if this is in wrong place please move it to proper place. Thanks

Go to John Deere - Parts Catalog. Type in 67 in the model line and see if there were mounting brackets made for a 790. If you Google the part numbers sometimes you can still find parts.