Need some help troubleshooting hydraulics

[Shredder]

The 3ph hydraulics on my compact IH 254 stopped working the other day after a weekend of shredding. No warning or nothing. I shredded, parked the tractor, and the next time I fired it up: nothing. No 3ph movement at all.

The only hydraulics on the tractor is the 3ph. I have some water in the oil and was gonna change it. I'm getting fluid moving through the system and some pressure from the pump.

Can someone help me troubleshoot this? I have very little experience with hydraulics but I have worked on other parts of the tractor and on various vehicles. The folks over at yesterdaystractors didn't offer much help. I think their threads get buried pretty fast, or something.

Norm

 

[zzvyb6]

Well, start with the mechanicals. Is there a valve lockout (twist knob)?. Are the arms up or down? Oil level up, filter plugged. hissing sound from a stuck poppet valve, bent control rod, rock or branch stuck in mechanism. Have at it tonight. call us in the morning.

 

[Kernopelli]

Norm, I have an '83 Mitsubishi MTE 2000D which is the grey version of your tractor. My 3 point quit functioning several years ago and it was caused by a roll pin that had worked itself out of the rockshaft that passes through the top of the 3 point hydraulic housing. The pin is located on the right side and is in the end of the shaft by the top lift arm of the 3 point. The pin holds the position control sensing rod. The rod runs to the lift control and is part of its linkage system. Unless the pin is loose and sticking out it is hard to see. I originally found this to be the problem by looking under the seat and you will be able to see the rod I am referring to, it is threaded with a spring on the end. With the tractor running, try using a screw driver or short pry bar and where the rod passes through that part of the control, move the control back and forth and see if the 3 point functions. You will probably need to have the 3 point lift control in the "up" position. If the 3 point works by doing this it is either the pin or the linkage is out of adjustment.

The 3 point on a larger Mitsubishi I owned quit suddenly and I found that the hydraulic control valve for the 3 point had a tiny piece of RTV sealant in one of the orifices inside. It was a pain to figure that one out but it saved buying a $900 valve.
You can find some of the schematics for your tractor at :
Case IH
Click on "parts and service" then click on "Begin your search for Parts right here", then enter the model number (254).
Hope this helps.

Darryl

 

[Shredder]

Well, start with the mechanicals. Is there a valve lockout (twist knob)?. Are the arms up or down? Oil level up, filter plugged. hissing sound from a stuck poppet valve, bent control rod, rock or branch stuck in mechanism. Have at it tonight. call us in the morning.

Thanks for the fast reply. I am not familiear with the "lock out". I'll have to read up some more before I can answer that. The arms are down. Oil level is full. I removed the filter; still no luck. I don't hear any hissing. I don't see any trash or sticks around the linkage. I'll look more in the morning when there is better light.

Norm

 

[Shredder]

Norm, I have an '83 Mitsubishi MTE 2000D which is the grey version of your tractor. My 3 point quit functioning several years ago and it was caused by a roll pin that had worked itself out of the rockshaft that passes through the top of the 3 point hydraulic housing. The pin is located on the right side and is in the end of the shaft by the top lift arm of the 3 point. The pin holds the position control sensing rod. The rod runs to the lift control and is part of its linkage system. Unless the pin is loose and sticking out it is hard to see. I originally found this to be the problem by looking under the seat and you will be able to see the rod I am referring to, it is threaded with a spring on the end. With the tractor running, try using a screw driver or short pry bar and where the rod passes through that part of the control, move the control back and forth and see if the 3 point functions. You will probably need to have the 3 point lift control in the "up" position. If the 3 point works by doing this it is either the pin or the linkage is out of adjustment.

The 3 point on a larger Mitsubishi I owned quit suddenly and I found that the hydraulic control valve for the 3 point had a tiny piece of RTV sealant in one of the orifices inside. It was a pain to figure that one out but it saved buying a $900 valve.
You can find some of the schematics for your tractor at :
Case IH
Click on "parts and service" then click on "Begin your search for Parts right here", then enter the model number (254).
Hope this helps.

Darryl

I have the seat and the other body parts above the hitch cover off already. I've seen the spring-loaded arm you're talkin' about. I'll look at it better in the morning and get back with ya. Thanks for the idea and link.

Norm

 

[Shredder]

@Darryl,

I checked this morning and I don't think my linkage has slipped as you described. I attached an image for you to look at. Hit me I misunderstood you.

Norm

 

[Shredder]

Well, start with the mechanicals. Is there a valve lockout (twist knob)?. Are the arms up or down? Oil level up, filter plugged. hissing sound from a stuck poppet valve, bent control rod, rock or branch stuck in mechanism. Have at it tonight. call us in the morning.

The IT shop manual doesn't mention anything about a lockout valve that I can see. There is an adjustment to control the speed of fall on the 3ph arms. All the linkage looks good; no bends or missing parts that I can tell. And still no hissing.

I guess I'm looking for general advice about whether I should consider this a pump problem or something on the other end. I can post images if that will help.

Norm

 

[Kernopelli]

Norm, The lock out valve that was referred to is described as the "flow control knob" under the "hydraulic lift system"/troubleshooting section of my I&T manual, it is the adjustment for the speed at which the 3 point lowers. If it is turned all the way open ( open should be all the way counterclockwise while looking at it) it lowers the hitch fast, turned all the way closed-it locks the 3 point on the down stroke) On my tractor it under and between your legs while seated, on yours it is probably on the trans housing behind the shift lever.

In the first picture you posted, I cant see if the pin is there or not. It is there to keep the plate on the rock shaft in a fixed position to push/pull the sensing rod as the rockshaft turns (if that makes sense to you) if the plate that the sensing rod attaches to moves freely (swivels) on the rckshaft- the pin has fallen out or sheared off, if it doesn't, it is probably not your problem. Have you tried to function the 3 point manually as I described? A better way to do that might be to take the sensing rod off at the rockshaft end by removing the cotter pin on the pivot. With the tractor running and the 3 point's lever in the fully or half "raised" position, manually push/pull the sensing rod and/or use a screw driver to push/pull the piece that the sensing rod goes through under the seat area. If the hitch works that will tell you if it is in the linkage system. If the hitch doesn't raise after doing this it could be a worn o ring in your pump, a worn control valve o ring, an obstruction in the control valve,bad o ring on the 3 points hydraulic piston etc.

Darryl

 

[Shredder]

Norm, The lock out valve that was referred to is described as the "flow control knob" under the "hydraulic lift system"/troubleshooting section of my I&T manual, it is the adjustment for the speed at which the 3 point lowers. If it is turned all the way open ( open should be all the way counterclockwise while looking at it) it lowers the hitch fast, turned all the way closed-it locks the 3 point on the down stroke) On my tractor it under and between your legs while seated, on yours it is probably on the trans housing behind the shift lever.

My "flow control knob" is in the same location as yours; just between my legs under the seat. I have not adjusted it in a very long time.

In the first picture you posted, I cant see if the pin is there or not. It is there to keep the plate on the rock shaft in a fixed position to push/pull the sensing rod as the rockshaft turns (if that makes sense to you) if the plate that the sensing rod attaches to moves freely (swivels) on the rckshaft- the pin has fallen out or sheared off, if it doesn't, it is probably not your problem. Have you tried to function the 3 point manually as I described? A better way to do that might be to take the sensing rod off at the rockshaft end by removing the cotter pin on the pivot. With the tractor running and the 3 point's lever in the fully or half "raised" position, manually push/pull the sensing rod and/or use a screw driver to push/pull the piece that the sensing rod goes through under the seat area. If the hitch works that will tell you if it is in the linkage system. If the hitch doesn't raise after doing this it could be a worn o ring in your pump, a worn control valve o ring, an obstruction in the control valve,bad o ring on the 3 points hydraulic piston etc.

Darryl

The rockshaft pin is still in place, unsheared. With the engine running at 1,300rpm, the 3ph lever in the up position, I was able to move the lever on the other end of the sensing rod with no affect. Nothing happened.

If there are no other easy options to check, of the other options you listed, which is the most likely cause of my problem? Or should I ask, which is the easiest to check? And, could the water in my oil have something to do with it? I have already changed it once, but could not get it all out the first time. I intended to change it again, but would like to fix my problem first.

Norm

 

[Kernopelli]

I don't think water in the system would keep it from functioning. Liquids don't compress like gases do ( Like having air in the line). Water might cause extended wear damage etc but unless a seal or something is already worn out, I would think water should allow it to make equivalent hydro pressure as oil, then again because it isn't as thick as the oil maybe it doesn't create as effective of seal.....

BUMMER. This is where it probably gets stickier. I would start by checking the hydraulic pressure. In the manual under "hydraulic lift system/ test and adjust" it describes how to test the system pressure. The relief is supposed to open at +/- 2000psi , so use a 3000psi gauge. They're pretty cheap- I paid about $15 for mine 4-5 yrs ago. See if the system is making 2000 or so psi. If not, check the pump, it is actually pretty easy to take off ( I know first hand unfortunately) and see how the seals look. If the system makes good pressure, I'd check the o ring on the 3 point's hydraulic piston. If that is OK then I'd check the relief valve to make sure it isn't stuck open and check the control valve for worn seals/ obstructions. I have had the latter of those problems on a Mitsubishi (grey CIH 284) I used to have, It had been "reconditioned" and they had used orange RTV sealant on the hydraulic case and a tiny piece of it found its way into the system and blocked a tiny orifice in the valve. It worked fine about the first 5 hours I owned it and suddenly quit like yours did. All this really isn't as hard as it all sounds, just a little daunting to think about doing it the first time. I had never worked on a tractor in my life when I had the problem with that 3 point but it turned out to not be too difficult using the I&T manual.Good Luck,
Darryl