AC 50/50 3 point hydraulic problem

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   I am struggling trying to figure out the issue with hydraulics on my AC 50/50. I have done everything I can think of with the same results. The 3 pt only travels about six inches. Remote works fine or so it seems. New pump, fluid, filter and flushed the system. Pulled the control head off and inspected all the components. Pilot valve is free and clean. The 3 point raises and holds, lowers, but only about 6”s. If I hold the hitch up the cylinder will fill but drops when I let go to height before raising. Any ideas??? 

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TCO Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 27 Jul 2022 Location: Michigan Points: 8	Post Options Post Reply Quote TCO Report Post Thanks(0) Quote Reply Topic: AC 50/50 3 point hydraulic problem Posted: 27 Jul 2022 at 9:53am
	I am struggling trying to figure out the issue with hydraulics on my AC 50/50. I have done everything I can think of with the same results. The 3 pt only travels about six inches. Remote works fine or so it seems. New pump, fluid, filter and flushed the system. Pulled the control head off and inspected all the components. Pilot valve is free and clean. The 3 point raises and holds, lowers, but only about 6”s. If I hold the hitch up the cylinder will fill but drops when I let go to height before raising. Any ideas???

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steve(ill) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 85767	Post Options Post Reply Quote steve(ill) Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 11:30am
	Does it seem like it just runs out of oil ? Can you hear the pump cavitate ? Does the system stall out and hit relief valve pressure ? Not a "well known" problem... Going to need some more data to help narrow it down... If you had a pressure gauge, that could also help tell you what is happening. slop in linkage...? https://www.allischalmers.com/forum/5050-hydraulic-problems_topic31534.html Edited by steve(ill) - 27 Jul 2022 at 11:35am
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TCO Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 27 Jul 2022 Location: Michigan Points: 8	Post Options Post Reply Quote TCO Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 11:40am
	I don’t hear relief valve opening, and the pump doesn’t change in sound at all. When I use the remote I can hear the engine load a little bit nothing when I raise the 3 pt. It functions like I was trying to raise the 3 point slightly. I have been threw the linkage and don’t see an issue there either. Control spool rotates freely and springs back. Could something be out of adjustment? Sensitivity or maximum arm travel? I wouldn’t think that either of those would help what I am experiencing

TCO Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 27 Jul 2022 Location: Michigan Points: 8	Post Options Post Reply Quote TCO Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 11:45am
	If it was pressure wouldn’t the remotes be effected also. They seem fine, and will bog the motor a little. The three point just stops no sounds just acts like that’s all it’s been asked to do

steve(ill) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 85767	Post Options Post Reply Quote steve(ill) Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 11:55am
	Tom, i know nothing specific about the 5050... was just trying to gather info " in general" for others to help out.... You use the REMOTE and you can hear the system hit relief or load up... you use the 3 point and it appears to just fill the cylinder and slightly lift, but you hear nothing....... That tells me the valve is bypassing and leaking back to sump, or the cylinder is leaking back to sump, as you can NOT BUILD UP PRESSURE... I dont even know if the cylinder is in the open and easily visible, or hidden inside the rear case... It could have blown a seal, etc...........other options are the control valve you are stroking is broken and leaking by, or the relief is stuck ( if it is seperate from the aux valve system).
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TCO Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 27 Jul 2022 Location: Michigan Points: 8	Post Options Post Reply Quote TCO Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 12:12pm
	I assume with no implements hooked to the remotes it wouldn’t take much oil the build pressure and load the engine. If a relief was stuck could the remote still operate. I know nothing about hydraulics except what I have read. Don’t mind buying new valves if I could narrow it down to which valve is. Lol The reliefs valves visually look good . Thank you for helping by the way!

steve(ill) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 85767	Post Options Post Reply Quote steve(ill) Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 12:14pm
	I found this on the internet... the guy had the same problem.. see post #25 about a valve being stuck....... If you go back a page or so, he says he found a manual on the system.. I have not read everything to see how the story ends... https://www.tractorbynet.com/forums/threads/help-troubleshooting-3-point-lift.376905/page-3
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DrAllis Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Points: 21406	Post Options Post Reply Quote DrAllis Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 12:18pm
	From the given description, it sounds like a linkage problem that won't allow the hitch to hydraulically operate in its full range of motion. Is the hitch fully DOWN and only raises up 6 inches ?? Is the hitch in the mid height range of position and will not go fully UP or fully DOWN and just hangs around in an area in the middle and six inches there ?? And lastly, you've owned this tractor for a while and it used to work just fine and now it doesn't ?? or you just bought it and figured out this is why the other guy sold it ??

steve(ill) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 85767	Post Options Post Reply Quote steve(ill) Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 12:18pm
	here is the manual ( same tractor as LONG 510)... takes a few minutes to download. https://tractorpoint.com/pdf/Long-Service-Manual-360-460-510-series.pdf
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TCO Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 27 Jul 2022 Location: Michigan Points: 8	Post Options Post Reply Quote TCO Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 12:55pm
	Thanks guys for all the responses. I have all the service manuals. I have manually, thru the inspection plug moved the arm and it has the same results. I think ruling out linkage. While observing lifting thru the inspection plug I did notice that oil is coming into the sump during lifting and continues after the big six inches lol. I think something is letting the oil bypass the cylinder, but the cylinder holds good after the six inches? So it seems that that the oil going although not enough holds but no more goes in just bypasses into sump? Does that seem possible?

TCO Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 27 Jul 2022 Location: Michigan Points: 8	Post Options Post Reply Quote TCO Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 1:03pm
	It goes fully down and only comes up about 6”. And I have had it along time it used to work

DrAllis Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Points: 21406	Post Options Post Reply Quote DrAllis Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 1:47pm
	Blown seals on the lift cylinder.

TCO Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 27 Jul 2022 Location: Michigan Points: 8	Post Options Post Reply Quote TCO Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 1:49pm
	Wouldn’t it not hold pressure even though only 6” if the cylinder seals were bad?

steve(ill) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 11 Sep 2009 Location: illinois Points: 85767	Post Options Post Reply Quote steve(ill) Report Post Thanks(0) Quote Reply Posted: 27 Jul 2022 at 3:07pm
	The internal cylinder probably has a flex hose going to it.. The hose cracked or the cylinder packing could be failed.... We have seen similar on a D17.... acts the same way... depends on how "BAD" it failed on how it reacts...... If you can see oil POURING OUT of the cylinder area while you are trying to lift, then you need to get inside and LOOK closer.
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