5000 hyd lift chest followup

A week or 10 days ago I was looking for a I & t manual to adjust the linkage on the lift chest. Found the use of one (FO35).Tractor is back together and running. Every thing functions as it should with one exception. I now have a (constant pumping) -- MF term-- position at the very top of the lift lever were the Ford operators manual says you over ride maximum lift. I can live with that but was sure something would be different as the adjusted lift chest according the the I & T manual made the adjustments quite different then they originally were! Either the linkage is bent or the I & T manual is not correct. I can see why the system does what it does but didn't figure out what the problem really is? OH,I saw here earlier someone pulling the plug for the unloading valve. In my case, I though I might be loosing threads in the plug or pulling bolt as it pulled so hard, but persistence prevailed!

Over here in England there were many changes to the adjustment, slip-gauges and linkage over the years in the 5000 models. There always was a constant pumping position beyond the top quadrant stop because that overrides the lift cylinder knock-off pin.

As long as everything works OK you will be fine.

I'm not aware of a *constant pumping* position on the 5000 control handle. One could accomplish that using the ASC valve and the corresponding port on top of the 3-point top cover, but not during normal 3-point operation.

If the tractor is *constant pumping* with the handle at the top of the quadrant, then something is out of whack. And no, that is not a good thing because the pump is constantly operating at high pressure, which will eventually destroy it.

Some questions for you:

1) What year is your tractor?
2) Did the I&T manual give you two possible control valve adjustment specs depending on the year of the tractor?
3) What depth did you ultimately adjust the control valve to?

Hi Bern,

The constant pumping beyond the top stop was there on the hydraulics from the time of the Dexta and Super Major. It was not used in normal lift operation but was used when driving hydraulic equipment and things like hydraulic motors. It overrode the knock off pin which would stop those pieces of equipment if the arms crept up and moved it.

The idea came from courses at Boreham, I don't know whether it carried on to the changed hydraulics in the 600 and 10 Series tractors.

That may have been the case with the original Super Major, however that idea was not carried over into the 1965 and up production tractors. Which is what I think of when the number 5000 is discussed.

I would either readjust or block it from going all the way to the over pumping mode.. as this will overheat the fluid, and add a lot of wear to the pump. If I understand it.. your trying to pick up a lift that has already hit maximum and its at the stop. And your trying hard to bend, break, blow out something and have the safety valve venting all the over pressure. Shorting the rod a bit will stop this at full lift.

The tractor is a 5200 year model 1972. It was 2 years old when I bought it. The I & T manual FO-35 is for 5000 5600 6600 6700 7000 7600 7700. And yes it took some reading to make sure we were in the right sections, Hopfully! I saw no differences between years in th manual. I built a guage of .200 of an inch, 5.08 mm per the manual, in the recessed position. measured at the front of the control valve with the plates off. Both draft and position setting were measured at that distance with the linkages in there proper mode. Says the manual. I went over the adjustments several times, knowing it was not close to were it was when taken apart. Nothing was removed except the cylinder valve body. Always had the feeling a linkage some were was over center but could never determine that one could actually do that. Well, it is together and a stop at the top so we will never get into constant pumping. The lift arms reach there maximum height but a small correction of the control lever moves the lift arms more than I though would be normal. It has not left the building yet as the strange draft control linkage of the 5200 needs to be fixed, plus a few other minor details, Like I noticed I left the switch on since yesterday, so a nearly dead battery today

Ford made a significant change to the design of the control valve in 1970, which required a different setting dimension. These changes were detailed in a service bulletin that came out in July of that year. I have a copy if you need to see it.

The old style control valves are adjusted to .200 inch, and the newer style, which you should have, to .030 inch. This explains why you thought the control valve was so far off. I'd bet it you went back in and adjusted it properly your problem would go away.

I worked on a 7000 recently with the position control response all out of whack. Someone had cut the threads off the end of the turnbuckle to get the .200 inch adjustment. I had to weld on a new addition to be able to get the adjustment back where it belonged at .030. All is well now.

Thanks for the information. Yep, that .030 setting would have made the difference. Surprising the I & T manual didn't cover that since it seem to cover 5000s on up. Well, it is together and at it's age (50) and my age(88) it won't be a big problem to much longer.

Not even the Ford manual has that info, but rather it's in a very obscure service bulletin, hence most people don't know about this change.

You're 88 years old? Congrats on still being able to work on it the first time. I can understand why you have no plans to go back in there again.