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Discussion Starter · #1 ·
I have an interesting problem that I can't seem to figure out. I was out the other day using the box blade and it hit a rock or got snagged on something. Immediately the 3 point goes all the way up. Seems to be higher than even the highest setting with the lever. However, it will not go back down. I left it for a couple of days and it did end up lowering but as soon as I turn the tractor back on, it goes all the way up again. Tried messing with the up/down levers and draft control but nothing seemed to help.

After doing some Internet searches, I found people with similar issues that said to check the linkages in the reservoir under the seat. After removing the top plate to inspect, I didn't see anything out of place or broken. I removed the oil and filled it back up but it is doing the same thing.

Of course I want to avoid taking out the control valve unit before trying the simple things first. Any ideas on what could be going on or things to check?
 

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I suspect what's happened is the "snag" has caused an issue with the draft linkage. I expect your tractor has top link sensing for the draft. The incident you mentioned may have applied excessive effort to the top link mount(which operates the draft system) and somehow altered something within this collection of springs, rods, and links which is now causing the lift to raise without control. My first fear is for the pump. If you continue to run the tractor without correcting this, it's possible the system may be trying to raise the lift arms beyond their range, thereby stacking up pressure and possibly damaging the pump. I'm not sure if I have a book on this particular model with which to offer any instructions on how to solve your problem, but if you intend to work on this yourself, GET ONE!
 

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IH used a rather complicated control valve for the 3 point, and if you bend the rockshaft it will bind, the valve will no longer sense properly, and will subsequently keep directing oil flow to the lift cylinder. So, the first order of business is to pull the rockshaft and check it to be sure it is true and not bent and binding.

If the rockshaft is true, and you have a good working knowledge of how hydraulic systems function, go to the on-line Case IH parts listing for your tractor and take a look at the diagrams for the control valve assembly for the draft control. You want to remove the valve, clean it, and then completely disassemble the control valve and check for plugged orifices, broken o-rings, and cracked springs.

If the rockshaft is bent, you likely can get it straightened by a machine shop for a reasonable price. But, when that happens and the control valve keeps pumping oil the lift piston generally will blow the O-ring and require repair.

If you are still learning about the hydraulic system, pick up a manual and use it to disassemble and inspect the control valve. The manual is available from:
http://www.ssbtractor.com/tractor_manual_display.cgi?m=International+Farmall&o=424
 

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Discussion Starter · #4 ·
Thanks for the tips. I will dig into it more the next couple of days and report back.
 

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Discussion Starter · #5 ·
Got some time to mess around with this again yesterday evening. As I was tinkering with the levers and banging away and things trying to figure out how the internals work, I heard a click. I looked in the reservoir and noticed that one of the pieces touching the linkage was sticking out more. According to the diagram this is #52 called a "plunger", which is part of #44 "spool". I assume this connects to some sort of valve that was stuck and preventing the hydraulic piston from releasing/unloading. Just wanted to note this in case others come across a similar situation.

 

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Howdy droz,

Welcome to the tractor forum.

Item #44 assembly may be your "unloader" valve, which if stuck can result in the lift arms being stuck in the "up" position.

Fedup makes an excellent point regarding the draft control possibly being jammed by hitting the "snag". On a Ford tractor, the top link of the three point links is the sensing element for hard pulls and/or impacts (it is pushed "in" with impacts). See if you can pry it outward.
 

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Hey droz,


What did you determine was causing your issue?


I have a '66 IH424 and have that same behavior with the 3 point being stuck in up position. I was using the loader bucket to haul material at the time when it started and nothing was on the 3 point besides a drawbar.


The isolator valve closed stops the movement as it should, and when left to sit for a day or two with the isolator valve open, the 3 point settles down to the bottom position when the position lever and draft levers are in full forward position. While this was going on, I tried to lower the hitch with both the position and draft levers.


The position lever moved forward normally but hitch stayed up, the draft lever had some significant resistance to movement compared to normal operation but did move to forward position.


I am hoping someone can provide some insight on what may be causing this before I open up the hitch reservoir/valve linkage to investigate so I have an idea of what to look for.
 

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Hey Guys,
i too have this problem. picked up my 1978 IH 46 from a guy that gave up on the problem. such a great little tractor. so any advice will help.
 

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Sounds like droz left when he got a replay.... happens so often, leaving many folks in a learch!
 

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Sounds like droz left when he got a replay.... happens so often, leaving many folks in a learch!
i'm on it... i already tear a part my body valve .. everything look ok in it a suspect the follow up system
i also need to replace the chain that hook-up the followup valve... will keep you updated
 

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Finally found the issue.... after removing, reinstalling, testing the 3 point control valve 10 times or more..
i found the issue was 3047 294 r95 orifice calibrated hole was blocked ...
simple as that...
 
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