B7800 ? about 3pt lowering down on its own

[Fjord]

I noticed that when I had the ballast box on (about 500 pounds) the 3pt hitch seemed to be slowly lowering down on its own.I checked and found that when everything was warm and at operating temperature it would drop 2 inches per hour (measured at the lift pins).When cold, about 1/2" per hour, and if I close the "lowering rate valve" about 1/2" in 12 hours.This isn't a big deal with the ballast box, but I imagine it might be a bit inconvenient when using a heavy implement.I asked the dealer and he said this is normal- just close the valve when set to the right height.If this is the case then I guess I'll accept it, but I just wanted to find out if anybody else has had a similar experience. My old IH used to sit for days with weight on the 3pt (and it's almost 50 yrs old!). Thanks for your help

 

[wushaw]

That's another good reason for having position control, it will keep the implement up.
It is the nature of the beast of non-position control.

 

[Timber]

Do you tighten the Hydraulic control knob between your legs after you set the hight My Ballast drum is over 800 pounds and it has never dropped on me and I have had it up for days at a time

 

[Fjord]

At first I wasn't closing that valve and that's when it was dropping 2" per hour.After I closed the valve it only dropped 1/2" in 12 hours.I was just wondering if dropping that much when the valve is not closed is normal.If it is, thats O.K. I just wanted to make sure there's not something leaking that shouldn't be. Thanks

 

[art]

To carry heavy loads on the three point hitch will put stress on the cylinder and valve that is carring the load. No different then if you had to carry extra weight all the time you would start to sag! It makes no difference as to the type of hitch control position control or 1/4" valve as any that carry heavy loads just like loaders they will all lower with time. To have a load check style valve which has never been used in this area or even on loaders would stop the problem. The reason they don't use the load check valves in these areas of the tractor is because there is no cushion to the system.

 

[wushaw]

To carry heavy loads on the three point hitch will put stress on the cylinder and valve that is carring the load. No different then if you had to carry extra weight all the time you would start to sag! It makes no difference as to the type of hitch control position control or 1/4" valve as any that carry heavy loads just like loaders they will all lower with time. To have a load check style valve which has never been used in this area or even on loaders would stop the problem. The reason they don't use the load check valves in these areas of the tractor is because there is no cushion to the system.

I agree with you on this if the tractor is parked and engine is off.
Position control will keep the height that is selected on a running tractor and a non-position control will not, you will have to occasionally raise the 3pt to keep the 3pt from dropping to the ground.
I have had both styles on a Kubota and this is the way they worked.

 

[DAP]

That's another good reason for having position control, it will keep the implement up.
It is the nature of the beast of non-position control.

Yup. Other problems with the quarter inching valve:

1. Known to cause tumors in lab mice.
2. If you own a PC valve, then trade for a quarter inching valve, you will sacrafice your male first born ...
3. All quarter inching valve owners have felonious criminal records. Most have permanently suspended licenses and cannot keep jobs.
4. Known to cause skin warts and other lesions ....

 

[DAP]

I agree with you on this if the tractor is parked and engine is off.
Position control will keep the height that is selected on a running tractor and a non-position control will not, you will have to occasionally raise the 3pt to keep the 3pt from dropping to the ground.
I have had both styles on a Kubota and this is the way they worked.

I think you should re-read Art's post. If your 3 pt sags while the engine is running (that runs the pump), then you have a bad valve, a hydraulic leak or both - regardless of the type of valve.

 

[DAP]

I agree with you on this if the tractor is parked and engine is off.
Position control will keep the height that is selected on a running tractor and a non-position control will not, you will have to occasionally raise the 3pt to keep the 3pt from dropping to the ground.
I have had both styles on a Kubota and this is the way they worked.

I think you should re-read Art's post. If you 3 pt sags badly while the engine is running (that runs the pump), then you have a bad valve, a hydraulic leak or both - regardless of the type of valve.

 

[Fjord]

Thanks for all the responses.
My understanding of the 3pt from a QEV point of view (and correct me if I'm wrong) is that the only time the pump pressure would have any effect is when raising the implement. The rest of the time the valve would just be holding it. As I observed, if it's going to sag it will do it whether the tractor is running or not, but maybe a bit more while running due to the oil being warmer and lower viscosity. I guess what I was trying to find out here is what "normal" would be on a new tractor. I don't want to find out in 3 years that there is a defect I could have had repaired under warranty, and at the same time I don't want to claim that there's a defect if it's acting normally. I'm very happy with the work it's doing for me (and the fun I'm having doing it) but I guess since it's new I'm still becoming familiar with its behaviours. Thanks again for all the input.