1985 Massey Ferguson 255 lift problem

[tdark]

I have having an issue with my MF 255.
After sitting for a while I seem to have issues with the lift. When I first start the tractor it just won't lift, even after it warms up. I can get off tractor and try and move the lift with my hands up and down and it seems to work. I then connect my harrow and it will then lift the harrow or bush hog and work all day.
I park it for a few weeks and same thing. I have changed the fluid and filter and no change. It just seems like something is sticking but don't know what. Any tips on what to check to maybe solve this ongoing issue ? Thanks

 

[Dman1981]

Are
You talking about the screen in the bottom
Of pump you can clean it's metal?
An easy check is to pull standpipe cover And with a rubber tip air nozzle blow air in it with levers in the up position.if you hear a lot of bubbles could be rings valves and orings on pump it's a lot easier to see if you pull top cover off. then you can look at linkage on cover and actually see where all the bubbles are coming from tops of valve bodies, control valve, pistons
What oil did you put in when you changed? needs to be permatran or equivalent

 

[tdark]

I haven't checked the screen at the bottom but I can if necessary. I was thinking it wouldn't work at all if plugged up. I only changed the filter that looks like an air filter . It sits on a stud. I should have been more clear about that.
I will check with the rubber tip air nozzle first and see what I hear. I will post back my results when I get a chance to do this.
I also used the oil that NAPA said would work for this tractor . They said it was compatible with permatran.
Thanks so much for your help.

 

[Dman1981]

If that screen is dirty
Will keep that from working is suction side. you can drain oil and reuse it also. Is a cork gasket on it if Your careful you can reuse it with a little silicone
Clean it really good with brake clean and re install same way you took it out

 

[tdark]

If that screen is dirty
Will keep that from working is suction side. you can drain oil and reuse it also. Is a cork gasket on it if Your careful you can reuse it with a little silicone
Clean it really good with brake clean and re install same way you took it out

I understand what you are saying but my question is how can it be a dirty screen cause my problem ? All I do is move the lift with my hands and it will work all day and never fail.
The fluid was not dirty when I changed it. It actually looked like new fluid.
This tractor sits under my shed most of the time . I only use it on occasion.
After sitting all winter of course it wouldn't work until I moved the lift by hand and then all was good for the rest of the day.
When I get a chance as I still work 10 hours a day at my shop I will check that screen anyway. I will post back results.
I do appreciate your help

 

[Dman1981]

Could also be linkage under covers rocking lifting linkage moves levers. or a sticky control valve. without pulling cover or screen I can give you lots of scenarios screen is easiest

 

[JD245]

I am working on a similar issue on my MF245, I'm trying to change the screen/strainer but since, I have auxiliary hydraulics coming out of the same cover plate it's making it very difficult to work around, so I might lift the whole cover. I would also suggest checking/cleaning the screen since it may be the easiest.

 

[tdark]

Thanks for all the help. I am really busy at my shop right now and this tractor of mine is not priority but I do hope I get time in the next month to check it out more.
I will try and do what was suggested and post back the results. Again thanks for the help.