MF65 Diesel 3-Point Problem

For several years, my 3-point has been slow to raise and leaks off pretty rapidly when the engine is stopped. Yesterday, the lift went all the way up and refused to respond the the control lever. It eventually leaks down with the engine off, but very slowly. I would appreciate any help possible with diagnosing the problem. Also, would like to know what all is involved in overhauling the pump and cylinder.

This forum has been very helpful in resolving my problems in the past and I am again hopeful.

Richard,
By your description, I'd hazard a guess and say that the pump control valve has jammed in the fully raised position. It can be a fairly common problem with pumps that are well used, the oscillator is broken or there has been an ingress of foreign material to the suction side of the control valve.
If you drain off approx. 10 litres of transmission oil, you can then remove the RHS centre housing side cover. It's the one with the trans. dipstick fitted to it.
Now, take a look inside. You will see two levers coming down from the top cover. These rest against a roller on the control valve actuating lever. Work the "position" lever on the quadrant thru it's travel. The actuating lever should move back and forth. If it fails to move, the valve could be jammed.
Try manually moving this roller and lever by hand, it may free up. If not, I would recommend removal of the pump complete, and rebuilding it, as you stated that it has been "weak" for some time.
To remove the pump, remove the lift (hitch) cover, PTO shaft and the dowel plates from either side of the centre housing. Now remove the split pin from the drive or shear tube attached to the pinion, and slide it back over the shaft coming from the transmission. Place the PTO lever into ground speed, and lift the pump out thru the top of the centre housing,
let us know your progress,
Evan.

I am having the same problem with a MF 65 Gas tractor. My control levers and the 3pt hitch were working just fine yesterday and then I went out today to haul some hay and the only way I can lower or raise the 3pt is by using the draft lever. My position control lever does nothing when I move it up or down. Any help please.

Evan, thanks for the quick reply. My wife had surgery and I have had no time yet to do the checks. I have studied the IT manual a little on the pump removal in case that is necessary. Hopefully I will get to it in the next few days and will let you know how it progresses. I think that I will also service the ram piston while I have the top off. Can you tell me if the necessary parts are available here on the site?

Evan,
I drained the oil down, removed the inspection plate and checked the things that you suggested. The levers moved and the roller lever moved also. The only thing that I noticed was that the filter was loose from it's base and was flopped over sideways. I guess that I will pull the top off and try to remove the pump. I will most likely be in touch.

Well, I'm back with an update of what happened. I tried to get the pump out the top and it absolutely refused to come. I ended up splitting the tractor behind the transmission and the pump came out easily. I disassembled the pump and found nothing broken or badly worn. Since the parts to rebuild the pump were over 50% of the cost of a pump, I replaced the pump with a new one. I put three new rings on the lift piston and new o-rings on the standpipe and under the lift cylinder. After putting it all back together it now works better than it has in the last 40 years.

In summary, all that I found was that all of the o-rings were hard and flat. I don't think that any of them could have held any pressure. I did all of the adjustments that the book called for with the cover off. The only adjustment that had to be done through the right-side inspection hole was the nut on the control valve shaft. My only conclusion is that the initial problem must have been associated with the pressure loss via the o-rings. The lift even stays up now and does not drift down. Thanks to all here for the assistance and moral support.