MF 135 Lift Arms Not Working

Norman Langford · Feb 10, 2012

I am working on an MF 135 where the hydraulic lift arms have stopped operating. Firstly I was advised to check and the clean the hydraulic oil filter. The lift arms, by the way were in the halfway up/down position. When I positioned both the Draft Control Lever and the Position Control Lever in their lowest positions to drain all of the hydraulic the oil, I noticed that the lift arms stayed in the same position whereas I would have expected them to drop to the lowest position.
I carried out the filter cleaning process without a problem, in fact the filter was not in the slightest dirty, but cleaning the filter had no effect on the problem. However I did notice that with the Draft Control and Position Control levers still in the down position, when the tractor was started up the lift arms rose to the high position and I could hear the oil pressure release valve operate when the arms reached the highest position. It then did not matter what positions I placed either of the levers in, the lift arms remained at their high position and would not move. However when the engine was switched off, standing on the lift arms caused them to drop to the lowest position irrespective of the position of the two levers. Again starting the engine caused the lift arms to rise irrespective of the position of either lever.
I figure that the problem is not with the pump, but something to do with the control valves operated by either the Draft Control lever or the Position Control lever, but I have no idea how to go about identifying the cause of the problem or how to rectify it. I would therefore appreciate and help I can get with this issue.

Anonymous-0 · Feb 10, 2012

Remove dipstick side cover, see if control levers will move pump roller lever, may be stuck control valve. Lift arms will drop with engine off, lift piston ring gaps will have slow leakdown normally.

DavidP, South Wales · Feb 10, 2012

Hi, as Rich has suggested it is necessary to remove the RH side cover to observe the operation of the pump lever (11) in the photo.
In normal circumstances the top of the pump lever will move rearward when you wish to raise the 3-pt. When lowering, the top of the pump lever is moved forwards into the discharge position. The neutral position is approximately halfway. To check if the pump lever is receiving the correct commands from the quadrant levers do as follows.
With the engine 'off' and 3-pt fully down ensure that the DRAFT quadrant lever is fully raised. Move the POSITION CONTROL lever to fully raised. Observe the position of the pump lever (11). The vertical lever (10) should allow the pump lever to move rearwards into the pumping position. Lower the POSITION CONTROL lever and the pump lever should move forwards to discharge.
With the PC lever down, start the engine. Nothing should happen. Move the PC lever up to about halfway. The pump lever should move towards pumping and the 3-pt will rise. As it approaches the selected position the pump lever should move to the neutral position. The 3-pt should then stop.
If the linkage continues to rise fully there would appear to be a loss of communication between the relative position of the 3-pt, the control valve in the pump and the PC lever.
This is often due to one of the two frameworks (the one attached to roller (9) or the one behind) breaking or bending. The rollers on the framework do not follow the correct track and so the command signal is lost.
If you are able to identify that the pump lever is not responding correctly to the quadrant lever commands then it will be necessary to remove the hydraulic cover to investigate further. Before doing this do NOT forget to remove the roller from the top of the pump lever.
A good manual is essential to go in further.
Let us know what you find.
DavidP, South Wales

Anonymous-0 · Feb 10, 2012

Hi Dave, I have a question about MF 100 series, Dad has MF 180 and still has the Pressure Control hitch that we used to use for pull type equipment for better traction. Was this also used much in UK? Have 4 John Farnsworth Books, also 1 of Stuart Gibbard, makes for good reading, but don't remember seeing any hitches in pictures. Thanks, Rich

DavidP, South Wales · Feb 11, 2012

Hi Rich,
Sadly the answer as to whether it was used much is 'no'. During the late 60's people were starting to use them and found them very useful.
The arrival of four-whel drive tractors all but killed Pressure Control. In most cases the 4wd would outpull the PC tractor and you could still mount something on the 3-pt if it was close enough and high enough. The two photos show the PC hitch fitted to my 1974 165. The hitch was purchased with a new 135 in 1965 by my neigbhour.
They putchased a new 165 ywo years later. The PC hitch is guaranteed NEVER to have been used. It was given to me in return for helping him when he needs some repair work done.
I have John Farnworth's book of 100 and 1000 Series tractors....a brilliant reference book.
As you might expect he was only interested in showing the tractors.
Cheers
DavidP

Norman Langford · Feb 13, 2012

(quoted from post at 18:51:29 02/10/12) Hi, as Rich has suggested it is necessary to remove the RH side cover to observe the operation of the pump lever (11) in the photo.
In normal circumstances the top of the pump lever will move rearward when you wish to raise the 3-pt. When lowering, the top of the pump lever is moved forwards into the discharge position. The neutral position is approximately halfway. To check if the pump lever is receiving the correct commands from the quadrant levers do as follows.
With the engine 'off' and 3-pt fully down ensure that the DRAFT quadrant lever is fully raised. Move the POSITION CONTROL lever to fully raised. Observe the position of the pump lever (11). The vertical lever (10) should allow the pump lever to move rearwards into the pumping position. Lower the POSITION CONTROL lever and the pump lever should move forwards to discharge.
With the PC lever down, start the engine. Nothing should happen. Move the PC lever up to about halfway. The pump lever should move towards pumping and the 3-pt will rise. As it approaches the selected position the pump lever should move to the neutral position. The 3-pt should then stop.
If the linkage continues to rise fully there would appear to be a loss of communication between the relative position of the 3-pt, the control valve in the pump and the PC lever.
This is often due to one of the two frameworks (the one attached to roller (9) or the one behind) breaking or bending. The rollers on the framework do not follow the correct track and so the command signal is lost.
If you are able to identify that the pump lever is not responding correctly to the quadrant lever commands then it will be necessary to remove the hydraulic cover to investigate further. Before doing this do NOT forget to remove the roller from the top of the pump lever.
A good manual is essential to go in further.
Let us know what you find.
DavidP, South Wales

Many thanks Dave for this. I guess I will have to drain the hydraulic oil to see all of this, is that correct. Regards Norman

DavidP, South Wales · Feb 13, 2012

Hi Norman,
Its not essential to drain the oil completely. From the full mark, if you drain about two gallons out to the level of the bottom bolt on the side cove you will be able to see what you need. Retaining some oil in the system will allow you to operate the quadrant levers and observe what response you get.
DavidP

Norman Langford · Feb 16, 2012

Many thanks Dave for the latest. This is a long range labour of love. I am located about 1 hours away from the tractor in South Africa and I get to the Vineyard only occasionally, so what would normally get sorted in a few hours can take days and weeks. It's a good job the tractor is not fundamental to the work of the Vineyard. Also do you know any locations for parts in this area. I have been using the guy near Bromsgrove and getting friends to bring parts out form the UK when they visit, so that delays things even more, but shipping here is a nightmare with things getting held up for weeks in customs. Regards Norman

MF 135 Lift Arms Not Working

Norman Langford

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