couchgrouch

Have 1986 MF250 Diesel Tractor- hydraulic lift isn't working right. Lift will rise, but will lower on its own when engine is revved just a little.

Background- I had to change hyd oil about 6 wks back, old oil was creamy-colored and lift quit working. Drained hyd oil, removed and cleaned pump strainer (approx 7" long) located under the rear chassis. [U]Found a cut O-ring on the base of the strainer- was not from the strainer[U].

Filled the hyd oil after cleaning and reinstalling the strainer; then tilled 2 small gardens. Tried to use the tiller about 2 wks later but the lift did not operate. Came back several days later and the lift would raise, but then go down when engine speed increased.

INFO-
Tractor has hyd Quick Disconnects, which we use for a wood splitter- it does work properly. (this was my Dad's tractor- I'm not a tractor mechanic)
I accessed the AGCO (Massey-Ferguson) parts book, but I can't locate hydraulic pump on the tractor. The book lists 2 hyd pumps with AUX hydraulics and 2 without AUX hydraulics.

1. Is there another strainer/filter, & if so, where is it located?
2. Any idea why the lift won't stay up when engine RPMs are increased?

Thanks in advance for any ideas/suggestions.

MDT

couchgrouch,
My neighbour has had some health issues and I have been helping around the farm. His MF 250's hydraulics will only lift after the tractor has warmed up for 30-40 minutes. The suction screen was cleaned and new oil installed about 3 months ago. It worked ok for a while but now that the weather is colder(in Nova Scotia, Canada) it is becoming quite a problem. Just wondered if you found the solution to your lift problem.
Thanks, MDT

shona13

Hi couchgrouch
Can You tell me what position all the hydraulic levers are in and what state the external hydraulic couplings are that is are the connected together etc Then I may be able to help .
Regards
Hutch.

MDT

Hi Hutch,
There is nothing attached to the auxiliary hydraulic connections. The draft control is all the way up or to the rear. The lift lever is up when we want the 3 pt. hitch to lift. Today after the tractor had warmed up for a while and the engine was running at about 750rpm the 3 pt hitch raised fully, then when the rpm's increased it settled back on the ground. Could there be a problem with the top link/draft control mechanism?
Thanks
MDT

shona13

Hi MDT.
It is possible there is something wrong with the draft/toplink assembly,To check ,with an implement attached to the three point linkage and the tractor on idle lift the implement and watch the toplink it should move out about 1/4 inch max ,if it does lift go to the rear of the tractor and keeping feet and other living things well away push down on the implement and see if it will go down if it does try lifting the implement up by hand ,if it responds you may have to remove the draft assembly from the tractor .
I recently replied to a post telling how to pull it apart , reassemble and adjust.
Generally the mark three pumps dont give any trouble with the control valve but anything is possible .
I hope this information helps .
Happy Days
Hutch.