External Hydraulic on tph

Jaypat88

Member
I am curious for what purpose does this hydraulic serve (see pic) other than raising and lowering one hitch arm and what would I use it for?

My TPH was none responsive and I removed my Hydraulic lift cover for examination. I found that my Hydraulic cylinder was cracked (see pic). Does anyone know what would cause this, so I don't break the new one? I ordered a new cylinder and Hydraulic filter, is there anything else I should replace while I have the cover off? I also have drained all the fluid since it had water in it.

Thank you!
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Did the studs break too or just the cylinder? An over pressure condition or bad adjustment will cause that. Check the lift arm for a shiney spot on the tip where it might have been hitting the differential housing. If its there then you had a bad adjustement problem and it was trying to over lift. Replace the pressure relief valve on the pump too while you are in there. If you do not have a manual get one cuz you'll have to do all the adjustments when you put it back together.
The cylinder in the lift linkage looks like someone removed the screw type level adjuster and put in a hydraulic one. Can't say i have seen one like that, not that it means much, but is interesting concept. I suppose you could have had a condition where the external cylinder was fighting the internal one and caused the internal one to break like that. Of course that is just a theory..
 
I've used a cylinder on the three point, but not on the lift arms. I used mine on the top link instead. Agree with rockepeg, check the relief valve system, it may be the cause. I've seen the cylinder ends broken off too from excess pressure.
 
The studs did not break. I just bought the tractor and it's hard
to tell if lift arms were hitting differential housing. Where is the
pressure relief valve? Is that the same as the pressure control
valve? (See pic). I have a manual and I can't seem to find it.
Is it associated with the response control or on the hydraulic
lift pump?
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Also my draft control assembly feels jammed. It will spin but
does not turn the overload stop inside lift cover nor does it
tighten or loosen. I am unable to pull on draft shaft when I
attempt to pull it out. Could the draft shaft be stuck and cause
the hydraulic cylinder to crack?
 
The relief valve is on the pump itself. Cost is about 20 bucks. As long as your stand pipe is straight then no reason to replace it. You will need to replace the orings and washers on the pipe though. Which model do you have and does it have pressure control setup or standard?
Can you clarify what you mean by the draft control assembly? Are you referring to the clevis, rod and spring at the tail of the top cover or the rod inside the top cover attached to the linkage with the adjustable stop?
 
Do you happen to have a part number for that valve? I can't
find it listed and does this site sell it? I have a MF 40
Industrial. How do I tell if it has pressure controlled or
standard?

This is what I was calling the draft control assembly. (Pic)
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Ah ok the draft control spring. So that setup you should be able to twist just a little and have no side to side or up and down movement if its adjusted right. You will not be able to move it in and out by hand. It will have no affect on the cylinder as its ony control is a rod on the inside that is connected directly to the linkage. In your picture there the stand pipe is in the lower right. If it's straight like that then you have standard hydraulics. If there is a block in line that has a hose coming off it then you have the other kind. There is a couple of pump options for that tractor and you'll have to look in the book and determine which relief valve you have.
http://www.agcopartsbooks.com/PartsBooksN/Viewer/book.aspx?book=agco/651282

Look on the left for the lift pump links and determine which is yours. Will be something like this:
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