3-Point Hitch 1970 MF 135 3 Point hitch adjustments after rebuild?

[Nevermore Farms]

Hi everyone, I am new to the list, just been looking around for tech help for a few years. finally have to ask:
I have a 135 with the diesel that had a bad three point hitch control problem that I lived with for years. the three point hitch would not stay in the same place-either always creep up or down. It was the final straw this summer when I was carrying a heavy piece of equipment and hitting a bump seemed to have pulled the dogbone from the internal cylinder out of the lift arm. I took the hydraulic system apart and repaired any damage and decided to replace the badly scored piston and cylinder (which may have caused some leaking and therefore creeping) and then decided that as I had no money into the tractor in years it was worth it to replace the hydraulic pump assembly to be assure that the valve body and any other internals were fresh and rule that out.

There was a missing spring on the one of the arms that interacts internally with the control levers. All of the rollers felt functional.
The manual was vague about adjustments before re-assembly. I only see an adjustable thumb screw on the pad that contacts the valve actuator.
in any case, now the hitch will only lift to maximum height if both draft and lift are all the way back. It is slow to lift and return.
The control levers appear to be mis labeled as there are several layers of stickers on them. Closest to the seat is labeled draft.

Should the lever that is closest to the seat have a lock in it before full lift? It currently does and i have to shift the lever around it. It does not correspond to the pictures in the manual.
if the right lever is in the middle of the range, the lift are does nothing.

So, My questions is in short: I only have full lift with both control levers fully up all the way. I have yet to run the arms with any weight on them. Will adjusting the depth of the plunger screw that contacts the valve body help add some control?

Thanks for any advice.

John

 

[Agvg]

There are a lot of adjustments and special tools to set up the hydraulic, you might hear what it cost to have a dealer adjust it, should not be more than an hour if you just bring the lift assembly. Draft should be all the way back unless you are using draft control. How are the state of your center link? There must not be any play in and out, if you do have that, then you will have issues with lifting.

 

[Nevermore Farms]

Thank you, That is an interesting option. There are no dealers local to me that I know of but I will look into it. i will look at the center link

 

[redman135]

Nevermore farms, are your hydraulics a draft and position control unit or a draft and position control AND preassure control unit? From the description of the constant creeping it sounds like you were using preassure control.
I don't know what year preassure control became avalible on the 135, however dads 178 was 1971 and had preassure control.
preassure and position control were both on the same quadrant (closest to seat).
Preassure control was fully forward = down and 1/2 way = full up.
Position control was fully back = down and 1/2 way = full up.
Did your tractor sound like it was under load with the seat side lever at the midpoint, and the draft lever in the full up/back position?
A photo of the quadrant would help.

 

[Nevermore Farms]

Redman, the picture is attached.

 

[jaxs]

Lift system adjustment require's several steps and can become really dry by the time you make your way through all of them. When one must go back and forth between hands on and written instructions it helps doing it in 3 or 4 sessions with a few hours to a couple of days in between.

 

[redman135]

Hello nevermore farms, That is a draft and POSITION control. BUT it is the first one I have seen with the draft on the seat side. All the others I have seen have the position control seatside and the draft control on the fender side.
Which lever do you use, the square or round head?
The lever stop on the seatside quadrant can be unscrewed and slid to the desired location up or down, usually up to set the upper height of the 3ph. There are some specific tasks where you want a reduced upper limit and sometimes you want to set a depth.
Note 1: there should be a lock top and bottom on each quadrant.
Note 2: On the right side by the diff lock pedal (behind your heel) is a responce control, shift that to fast and see what happens. You may need to clean the area to read the control.
WHEN you put an attatchment on you will need to adjust the down speed as a heavy attatchment like a backblade will hit the ground hard otherwise. But with no weight on the 3ph it will be very slow to go down.

 

[Agvg]

Quite shore the labels are wrong, draft is the outer and position is the nearest.

 

[Nevermore Farms]

I suspect the labels are wrong. The left side control is most responsive, currently only allows the lift to go fully up with the right round lever all the way up. What is a mystery to me is that there does not seem to be any adjustable components inside besides the thumb screw at the pump actuator

 

[Agvg]

Draft must be all the way back as on the picture so its disabled when you use posision controll, posision controll works on on the upper half of the quadrant, the lower is pump controll, contant pumping and pressure adjustment.