71IH

Member
Hey guys,

Working through an MF85 with the diesel I got running after sitting for years, thanks to everyone's help here.

It has a PTO pump that powers a loader, pto functioned in eng/and gnd drive when the machine was parked. Power steering was
functional, but the 3 point was slow/basically not functional. I went through and cleaned the PS return filter, aux pump filter in
transmission, and the power steering pump inlet and drained the old fluid. I also cleaned the drain plugs.

It was awful and the filters were caked with debris. I flushed a bit more of the old fluid out with some diesel and then placed in
7-8 gallons of diesel for a flush. I got the 3 point to work great/as normal. The power steering though reminds me of an air locked
automobile now, where as before it seemed to work fine/be smooth. I went lock to lock a few times, but it didn't seem to make a
change. The pto still does not spin with the tractor in neutral/at idle, while in eng pto. I do not see the dash light activating,
but I expect that it because of it being burnt out.

Is it possible that 7-8 gallons of diesel isn't enough fluid? Or that air is trapped in the system? Any other thoughts of stuff to
check? Should I just give it more time to flush?

Any thoughts on why an eng PTO wouldn't work after a tractor has sat, but was otherwise working great before? I'm starting to think
I am only left with clutches, or a line issue.

At present I am considering ditching the PTO pump, running the loader off the center mounted spool/aux pump and then just running
the PTO in gnd drive since it will only ever power a brush hog.

Thanks
 
System needs 11 gallons in the rear to be full. Power steering return oil is pressurized to about 175 PSI to operate the PTO clutch pack, No power steering means NO PTO. The PTO clutch pack on 85, 88, and Super 90 tractors has a large brake spring inside, with engine off the output shaft should not turn easily by hand. Brake is released when drum is pressurized with lever in engine PTO position. Sad thing is MF did not have a PTO pressure tap at the clutch valve for testing.
 
i had bought a 85 that sat out for many years, and the pto line inside case had froze and busted. its sits in the bottom of center housing and usually will fill with water from setting out In weather. take off p/s pump and look behind it and you will see a steel tube I think it is 1/4 inch in may be busted or split . you will need to split the trans and the clutch housing because there are two lines that feed the pto clutch. the red light was always on in dash indicating low p/s pressure.
 
Yup, that would do it. I had a Super 90 years ago at the dealer I worked for, the FRONT line front curved end popped out of the transmission input cover. It can be seen with the power steering pump removed. After a split to remove the cover, pulled the line, re-bent it slightly longer than needed so it was under tension when it was installed. Service manual gave an overall length for the line, will have to see if I can find it. The transmission needs split from the diff case to replace the rear line section.
 

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