MF 50 hydraulic lift

[Fentenetty]

Folks, I have a 50 continental gas that has had some three point lift issues. Because the arms never raised fully I robbed a cylinder off a baker and made a power top link to get my 4x5 bales off the ground for transport. I recently installed a hydraulic two spool controlled since my big tractor has been in the shop and needed the rear remotes.
While moving the bale I hit the control to take up the creep on the top link and heard a loud pop. The threads stripped out of the plunger and my lift arms raised all that up but will not respond now. Up or down. After setting two days, they have bled down half way. From my research on this site I suspected a stuck valve internally on the pump but would it still bleed off if so? I sort of wanted some input before I started it up just in case.
I should also mention that for several years my draft has been funny acting. I can not raise my draft control lever all the way up or my lift arms max out and cause the pump to strain. Even with position lever in lower. Any advice would be appreciated. Thanks.

 

[John Deere D]

Folks, I have a 50 continental gas that has had some three point lift issues. Because the arms never raised fully I robbed a cylinder off a baker and made a power top link to get my 4x5 bales off the ground for transport. I recently installed a hydraulic two spool controlled since my big tractor has been in the shop and needed the rear remotes.
While moving the bale I hit the control to take up the creep on the top link and heard a loud pop. The threads stripped out of the plunger and my lift arms raised all that up but will not respond now. Up or down. After setting two days, they have bled down half way. From my research on this site I suspected a stuck valve internally on the pump but would it still bleed off if so? I sort of wanted some input before I started it up just in case.
I should also mention that for several years my draft has been funny acting. I can not raise my draft control lever all the way up or my lift arms max out and cause the pump to strain. Even with position lever in lower. Any advice would be appreciated. Thanks.

I would remove both side port inspection plates,(as per pictures)after I drained some oil out.
Then view the internal components.
There should be TWO vertical levers on the FORWARD side of the actuator arm..see pic..

 

[Fentenetty]

Thanks JDD, it’s just quit raining so I’m goin out to get started. The bypass on the aftermarket valve spools seems very stiff. I’m gonna remove and replace with factory plate first to eliminate the easy stuff. Appreciate the pics!

 

[Fentenetty]

Strange, I pulled the valve block off and reinstalled the tube and top cover plate now there’s no response at all with draft or position. I can’t get my mind to understand that.

 

[John Deere D]

Strange, I pulled the valve block off and reinstalled the tube and top cover plate now there’s no response at all with draft or position. I can’t get my mind to understand that.

As per pics...........
YES, I have installed the OIL supply tube,and it was NOT in the Oil supply PORT...
NOTE position of control levers on Hydraulic pump control VALVE..

With inspection plates removed......and engine not running....move the MF three point "quadrant lever up and down", (See Picture)watch to verify the two levers on the Hydraulic pump control VALVE are in deed in the correct location,and are moving the pump control VALVE.

IF the pump control VALVE...... is NOT moving......then NO OIL PRESSURE shall be directed to its respectful port/ports.
Bob..

 

[Fentenetty]

I can’t tell you how much I appreciate the pics and help. Got it tore apart and, 1 I did indeed miss the hole in the pump, 2 one of the shafts had popped out of the hole it slides through, 3 once I popped end of shaft back in I noticed that my levers do not locate side by side but in single file. I’ll try to send pick.
Seems like everything is sloppy but possibly something is just bent throwing one in front of the other.
Again, thank you!

 

[Fentenetty]

Well I’m working on getting the draft plunger out and noticed the cam on the shaft the lift arms hook too is grooved where the roller rides. No other wear point is like that. Can this 3/32 groove be made up for with linkage adjustments? My wife is bound to cut me off soon so I’m trying to limit new parts to what is “have to have”.
Any tips in getting the spring and plunger out? Many I read about just cut it and replaced, but again, I have more time than money.
I need to add it is the early model style. I got the two Allen bolts out and one was broken which could have been part of my draft issues. Boot is gone hence the need for removal of entire assembly.

 

[John Deere D]

I have never seen an OIL pump in a MF 50 like your pictures show. I believe your 50 has had a new upgraded pump with an INLET SCREEN installed at some time??
Pictures # 1& 2 are the pumps I have seen in MF 50's.

Pictures 3 & 4 is the upgraded pump with an Inlet oil screen. Looks like one of your pictures

Picture 5 is of the faulty pump I replaced.

POSSIBLY, someone shall explain how to dissemble / remove the component you refer to as draft plunger .

 

[Fentenetty]

I’m referring to the rear top link part. With the rubber boot and large spring and plunger.

 

[John Deere D]

I’m referring to the rear top link part. With the rubber boot and large spring and plunger.

Sounds like my explanation was not as per your concerns.
I have seen pictures of a cutting touch removing the components your are asking about.

 

[Fentenetty]

Sounds like my explanation was not as per your concerns.
I have seen pictures of a cutting touch removing the components your are asking about.

Well a bit of update. I adjusted everything best I could and replaced what was needed. When I fired it up the lift arms rose up with no response to levee position until a loud bang occurred about the same time I got the key off. I panicked and couldn’t get on the clutch or something could have probably prevented whatever caused the bang. So my question is, what determines the cut out on the pump? It seems mine is not stopping. Also now my levers are all jacked up again. It looks from your pics I must have a 35 pump installed, unfortunately the fella who worked on it 25 years ago passed away in an automobile accident last year.

 

[Fentenetty]

Well a bit of update. I adjusted everything best I could and replaced what was needed. When I fired it up the lift arms rose up with no response to levee position until a loud bang occurred about the same time I got the key off. I panicked and couldn’t get on the clutch or something could have probably prevented whatever caused the bang. So my question is, what determines the cut out on the pump? It seems mine is not stopping. Also now my levers are all jacked up again. It looks from your pics I must have a 35 pump installed, unfortunately the fella who worked on it 25 years ago passed away in an automobile accident last year.

Also, what service manual would you recommend? Thanks.

 

[John Deere D]

Well a bit of update. I adjusted everything best I could and replaced what was needed. When I fired it up the lift arms rose up with no response to levee position until a loud bang occurred about the same time I got the key off. I panicked and couldn’t get on the clutch or something could have probably prevented whatever caused the bang. So my question is, what determines the cut out on the pump? It seems mine is not stopping. Also now my levers are all jacked up again. It looks from your pics I must have a 35 pump installed, unfortunately the fella who worked on it 25 years ago passed away in an automobile accident last year.

After any maintenance of any kind on my MF 35 Hydraulics,....

I always make sure the Fuel / Ignition is SHUT off .

"my tractor has a Perkins diesel"

Then crank the engine over on the starter, with the three point lift lever in the full down position.

IF arms stat to raise....there is a problem !!!!! Stop cranking the engine !

Picks of fractured cover,was donated.... a "YT" individual who started his Tractor up......after it had not be operating for a very,very long time frame.
Control levers and or relief valve possibly not functioning!

 

[Fentenetty]

A valuable lesson that will not be forgotten. I believe when I get my cover off it will be a mess in there. At least one of the studs holding the cylinder on stripped through the nut.

 

[Harry in Ky]

Are you sure the vertical links are on the right side of the control valve roller? It's always a good idea to work the draft levers a few cycles with the cover off before firing it up. Nice to know the levers and control valve are working full stroke both ways. Also a functioning relief valve should have prevented the cylinder studs from breaking. Might as well add that to your next parts order list.

 

[Fentenetty]

I was very certain to get the levers on the correct side. I replaced the top link draft plunger and wasn’t sure about the adjustment. I wonder if it could have caused it? Yep, I thought to myself when I replaced all those parts “what could go wrong with a pop off valve”! Wish ida spent the 20$ now.

 

[Harry in Ky]

Questions concerning adjustments? All the more reason to work the draft levers and watch the roller with the side cover off before starting it up.