MF 135 3pt. implement wont stay up

[ThistleRock]

Re: MF 135 3pt. implement wont stay up - Mine will not go down!

So, long story short, WITHOUT a service valve, you should be using the "square knob" lever (only) for MOST of your 3-point hitch control functions, with the "round knob" lever left in the raised position. When using soil engaging implements (ie a plow) and draft control is needed, use (only) the "round knob" lever to control the hitch and leave the position control lever in the "transport position" (raised). WITH a remote service valve, ALWAYS leave the "square knob" lever in "constant pumping" position (fully raised) and control the 3-point lift with the right hand lever on the service valve under the seat. That function WILL NOT provide "position control". Draft control function will be the same as is without the service valve, using the "round knob".

Thanks for that straight forward information!
I understand the controls much better, even if I don't have the remote service valve to worry with.

My problem is the opposite of "MF 135 3pt. implement wont stay up."

Twice now my MF 135 implement has refused to go DOWN.

The latest episode happened when I started the tractor just to keep the battery charged as I do when I have not used it lately. As always when previously being shut off I had lowered the attached implement (box scrape) to the ground with the inner position control lever. The outer draft control lever was fully up. Meaning that the control lever was in the lowered position before starting it as I mentioned above. Well, once started - which it does very easily, the heavy box scrape immediately rises to the highest lift position. changing the lift control lever would not change the position of the implement up or down.

I continued to let the engine warm and after 20 min. no change. However, I did have the slight feeling that the engine was straining (or possibly the hydraulic pump).
I shut it off and by morning the box scrape had drifted down to the ground. Like last time I am hoping that everything will be back to normal when I use it today for a little gardening.

Would you have any ideas of what is causing this, or if there is a DIY adjustment you would recommend?

This is my first tractor which is 42 years old. My father in law had given it to me recently and I would be imbarassed if I could not keep it in reliable running order as he has for all this time. Any help would be very much appreciated.

 

[Soundguy]

sounds like a valving problem.

I'm not familiar with the internal valving of that machine.. wheter it has an exuahst type valve.. or something mor elike an unloader.. either of which, depending on what it has.. could be the problem. restricted EV or sticky unloader.. etc..

 

[ThistleRock]

Thanks for the reply!
That will give me a starting point for research!

As I thought, the implement was on the ground the next morning
and the problem did not repeat itself while using the tractor the whole next day.