davidheal

With an implement attached to the 3 point linkage the lift and auxiliary hydraulic feed respond normally for the first few minutes but then start to slow down and after working for about half an hour struggle to lift at all, although they manage eventually. My local repairers have confirmed that the pump is working normally and the filter is clear so I assume that pressure is escaping somewhere in the system as the operating time or temperature increases. Any suggestions about possible causes or where to look would be much appreciated.

shona13

G,Day davidheal.
I would fit a temporary hydraulic pressure gauge to monitor the hydraulic pressure ,you can fit the gauge under the seat on the left or right hand side ,the left is easier remove the horizontal allen headed grub screw the thread is 3/8 bsp/npt taper thread use thread tape to seal the threads. the gauge should be good for 3000 psi. If you fit the gauge and monitor the pressure and come back and tell me what it is doing I will be able to tell you more .
Hope this helps
Regards
Hutch.

davidheal

Hutch, thanks for your advice. Things have moved on since my original post - (the pressure test had already been done and a reading of around 2500 psi obtained) - and the following may help others with a similar problem. We removed the top link connection and replaced it with a chain from the implement to the tractor frame. The lift then worked as it should, with the arms going up and down normally. As soon as the top link was reconnected it slowed right down. We then found that there was some end play in the top link connection which suggested that the control spring needed adjustment - a simple enough job according to the workshop manual, but in the event corrosion prevented easy removal of the retaining nut and the lift cover had to be removed, some parts replaced and the pump/linkage reset using special MF equipment. This work was carried out by the local repairer and it appears to have cured the problem. The key to the diagnosis was testing the lift after removing the load from the top link - the mechanic had come across this once before with another make but never with a Massey Ferguson. It's a simple 5 minute test that could save a lot of time and trouble investigating the pump and other parts of the system. Dealing with the adjustments sounds quite complicated and I'm glad that I handed it over to someone else to sort out!
Regards
David

shona13

G,Day David
I am glad to hear you trusted the job to a mechanic with experience on tractors .
I have suggested on more than one occasion on the site that sometimes money can be saved by using a tradesman with tractor knowledge .
I would like to think your comments will help other members .
Thank You and have a good day
Regards
Hutch.