MF 168 diesel from 1976 with Multipower, factory hydraulic for a front end loader. I bought it two years ago at 3100 hrs. NOw at 3200 hrs somewhat suddenly the 3-pt lift started to jump or oscillate around the desired lift level.
The jumping is not present when I sink the arms and set the pressure to low, also they saturate with very little bounce (vibrations could be sensed though) when rising the arms to max level and also when moving lever to constant pumping for a second or so. But otherwise the end of the arms witout any load is jumping almost an inch up and down.
The frequency of the oscillating is correlated(well 1 to 1) to the engine rpm.When placing a load on the 3-pt the whole thing
feels like a machine from hell. It started bouncing and after a second I got a flat front tire. (Then hooked off the load from 3-pt) Tried to use some auxillary hydraulic to run a log splitter. Didn't work. Connected and open hose
to the quick connector outlet (3/8") and no oil came out no matter how I moved the control levers. During the above, the selector vault on the right
side just below the seat, is pointing backward so the two circuits are not connected. And also, in this position I don't notice any bouncing operating the rams of the front end loader. And the MP and PTO clutch seem to work. If I push the selector vault forward, the front end loader starts to bounce when moving the rams.
Changed oil, changed filter cart. and cleaned screen filter located onto the pump. No difference. This behaviour don't change after operating the tractor for a period of time, so its not related to oil temperature what I belive.
The oil looked ok to me. At the low points in the reservoar there were some form of old mud or so ( a couple of tea spoons) and the screen filter was partially covered by something white that reminded me of nylon/cotton.
Under the seat cover I almost see a couple of pipes connecting to the top plate but I also notice that this pipe/pipes are vibrating
with something that feels like high preassure. Also, the 3-pt is not sinking fast when parking
the tractor. If the selector level is pointing backwards and no load on the 3-pt typically almost one week from max to min. I think it's the main hydraulic pump - or a component in that circuit.
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