Ford 1210 with 3 point that won't go down...

[sandman2234]

I am wondering...
Since the lift arms came down when the head was off, is there a possibility that there is something clogged up in the return oil system? The oil has to go somewhere, and while it took some effort, the lift arms did go down when the head was off. In hindsight, I probably should have cycled the lift arms up and down several times in order to free them up, but was just so glad to have them go down, that I didn't think about it. Had I cycled them up and down several times, it would have eliminated Harry in Ky's (and mine) thoughts that the splined shaft called rod (4) is stuck in the bushings. Now realizing that the bushings are there and it is not shaft to housing (dis-similar metals), I now realize it isn't steel to aluminum. However, the rod to bushing could still very easily be stuck.
When running, as I raise the handle to raise the lift arms, I can hear the diesel engine loading down, and if I lower it, the diesel engine loading sound goes away. So while that should mean something, I am not completely sure exactly what it means.
1) is the pump loading to max and stalling?
2) is the unit low on fluid and unable to pump the volume of fluid that is needed to actually move the cylinder?
3) If the return oil port is clogged, would that matter as long as the piston was in the up position? Seems like fluid would continue to pump into the cylinder chamber, thereby pushing the lift cylinder down before a clogged return port would matter.
4)Due to it's being left in the auxiliary position for an unknown amount of time, is it possibly that the pump has been damaged, and will pump volume but not pressure?
5) Is a relief open somewhere, not allowing fluid pressure to build up?
6)Is something in the head, such as the hydraulic valve (21) not installed correctly? I removed it, and replaced it, and there doesn't seem like anything is out of place. However, since it has been gone into before, it could be me missing something.
I am thinking my next moves should be to go after hydraulic fluid, figure out what I did with the broken dipstick (currently has a rubber freeze plug in hole to prevent rain and dust from entering) and get the hydraulic fluid level up to the correct level. Start tractor and see if anything happens when I raise the lift arms.
If nothing happens, pull the head back off and see if the lift arms can be raised and lowered with the M7040, and then cycle it a few times.
I priced the lift shaft assembly in a used part, when I was looking for a dipstick. It wasn't as bad as I expected, only $800! However, they want a $600 core charge on it, which means I have to ship the old one back, plus loose those extra parts. Plus, with these additional parts costs, I am exceeding the value of a running tractor with what I have invested in it, something I was hoping not to do.
Thanks for all the help!
David from jax

 

[sandman2234]

I disagree. The problem is between bushings (item 2 and item 3) and shaft item 4. The arm, rod, and piston are merely going along for the ride. The piston seized in the cylinder bore is a possible, yes, but I'm betting on the shaft.

I didn't see any corrosion around the piston, but it was at the lowest position, so any corrosion could be hidden. Removal of the head a second time now that it has gone up may show a different story.
David from jax

 

[JC-jetro]

I disagree. The problem is between bushings (item 2 and item 3) and shaft item 4. The arm, rod, and piston are merely going along for the ride. The piston seized in the cylinder bore is a possible, yes, but I'm betting on the shaft.

I can see bushing 2 and 3 against rockshaft is seized up and that must be one heck of seizing, but David was able to lower the arm aster head was removed. I suggested to heat the area a bit externally and spray some penetrating oil might help. This is very abnormal.

 

[Harry in Ky]

I don't know what removing the head again will accomplish. I think you can just remove the fittings etc from the head and relieve any hydraulic pressure in the cylinder. Then go back to forcing the arms up and down. I think it will take more than just a few cycles to make much headway.

I ran into this once an a little Massey tractor that was so tight I had to remove the housing, fabricate some puller brackets and push the shaft through with a forcing screw since it was too awkward to fit into a press. I could move it part way until it would go no more, hose it down with penetrating oil, move the apparatus to the other side and force it back the other way. Repeating that process numerous times, each time getting a little bit farther before it bound up I was eventually able to get the shaft out. Once apart, the rust and crud cleaned out, the shaft was actually slightly loose in the bushings.

 

[JC-jetro]

I am wondering...

David from jax

I am wondering...
Since the lift arms came down when the head was off, is there a possibility that there is something clogged up in the return oil system? The oil has to go somewhere, and while it took some effort, the lift arms did go down when the head was off. In hindsight
yes That is what I was saying that the trapped oil through spool valve is what keep the arm to go up and returning the same oil from the same path to spool valve will dump it in to diffy and lowers the arm.

, I probably should have cycled the lift arms up and down several times in order to free them up, but was just so glad to have them go down, that I didn't think about it.
Had I cycled them up and down several times
Perhaps you should have as I suggested it. I was hoping it causes to un-clog something.

, it would have eliminated Harry in Ky's (and mine) thoughts that the splined shaft called rod (4) is stuck in the bushings.
i see the possibility but to my estimation must be real rare occurrence.

Now realizing that the bushings are there and it is not shaft to housing (dis-similar metals), I now realize it isn't steel to aluminum. However, the rod to bushing could still very easily be stuck.
with the head removed, area of rock shaft heated and sprayed on lubricant you might want to manually raise it up and down to see if it gets easier.

When running, as I raise the handle to raise the lift arms, I can hear the diesel engine loading down, and if I lower it, the diesel engine loading sound goes away. So while that should mean something, I am not completely sure exactly what it means.

That means you are pumping against a dead head. When the lift height is achieved all the oil must be returned to diffy from the spool valve. the only time you get oil to lift cylinder is when you raise and then stop. that is all the lit might need. The spool valve will go to a neutral position with a feed back control linkage and all oil will be dumped internally in the diffy.
1) is the pump loading to max and stalling?

pumping against a dead head will stop the engine. Your gear pump is directly splined to your timing gear and flywheel. there is no slippage. Liq oil is not compressible so all the pressure trapped will bog down the engine. Usually in a case like this the releif pressure device would dump oil in to diffy just as a means of pump protection.
2) is the unit low on fluid and unable to pump the volume of fluid that is needed to actually move the cylinder?

Only if the pump is cavitating because gear pump can push fluid but not air and foam.

3) If the return oil port is clogged, would that matter as long as the piston was in the up position? Seems like fluid would continue to pump into the cylinder chamber, thereby pushing the lift cylinder down before a clogged return port would matter.
if the return path is clogged then there is no flow but higher pressure. I am not clear with your statement here.

4)Due to it's being left in the auxiliary position for an unknown amount of time, is it possibly that the pump has been damaged, and will pump volume but not pressure?

No, it will cause the pump to be damaged. pump volume against the relief pressure device will set your system pressure. if relief device is set higher that pump spec then pump internal seals will blow up and gear to gear heat generated will destroy the pump. with positive displacement pump you either have flow or a dead pump.
5) Is a relief open somewhere, not allowing fluid pressure to build up?

Yes, but that has to be the very first relief you have on the discharge pipe from the pump.
6)Is something in the head, such as the hydraulic valve (21) not installed correctly? I removed it, and replaced it, and there doesn't seem like anything is out of place.
21 is a conical valve tat regulate the rate do drop, so if that knob is closed then is return path is blocked and no dropping of the arms,
However, since it has been gone into before, it could be me missing something.
I am thinking my next moves should be to go after hydraulic fluid, figure out what I did with the broken dipstick (currently has a rubber freeze plug in hole to prevent rain and dust from entering) and get the hydraulic fluid level up to the correct level. Start tractor and see if anything happens when I raise the lift arms.

yes, you do not want to run the pump dry causing a major headache and $$$.
If nothing happens, pull the head back off and see if the lift arms can be raised and lowered with the M7040, and then cycle it a few times.

Yes , I agree.

I priced the lift shaft assembly in a used part, when I was looking for a dipstick. It wasn't as bad as I expected, only $800! However, they want a $600 core charge on it, which means I have to ship the old one back, plus loose those extra parts. Plus, with these additional parts costs, I am exceeding the value of a running tractor with what I have invested in it, something I was hoping not to do.

Let's hold off on buying anything yet. Need to find the cause first.
1- did you remove the lift piston.
2- did you see the ram rod.
3-did you try to move up and doen the lift arm with no weight while piston and head removed?

 

[rScotty]

I don't know what removing the head again will accomplish. I think you can just remove the fittings etc from the head and relieve any hydraulic pressure in the cylinder. Then go back to forcing the arms up and down. I think it will take more than just a few cycles to make much headway.

I ran into this once an a little Massey tractor that was so tight I had to remove the housing, fabricate some puller brackets and push the shaft through with a forcing screw since it was too awkward to fit into a press. I could move it part way until it would go no more, hose it down with penetrating oil, move the apparatus to the other side and force it back the other way. Repeating that process numerous times, each time getting a little bit farther before it bound up I was eventually able to get the shaft out. Once apart, the rust and crud cleaned out, the shaft was actually slightly loose in the bushings.

I'm recalling this same problem on TBN from a few or maybe ten years ago...might have been longer. It was either a small Ford (Shibaru) or Yanmar...I think.

Anyway, In that case the arms couldn't be lowered and the problem was mechanical interference. The piston rod had come loose - I'm not sure which end - and was trapped under the rockshaft. I believe that it had broken part of the skirt of the piston as well - but thatthe piston was still usable.

Looking back at the diagram you posted, I'm betting that what happened is that the lift arms were lifted up too high and the piston rod came loose and is trapped under the shaft - I think that to make that happen Pin 14 would have to shear or cotter 15 come loose. Or a similar situation where the rod connects to the piston.
I have heard of - but not seen - a situation where the rod is not affixed to the piston. The rodjust fits into a socket on the underside of the piston and can jump out if the arms are forced up too far. Normal tractor operation would never force the arms up to that extent.
luck,
rScotty

 

[Harry in Ky]

"Heard of - but not seen"? I'm not aware of any lift pistons being attached to the con rod. Any tractors I've had apart the rod is connected to the rock shaft arm but free on the other end. I'm not aware of any where manually raising the lift arms will cause the rod to fall out of place and get trapped somewhere. If you know of any what might they be?

 

[JC-jetro]

I share the same opinion that the rod and piston should not be permanently attached or one piece but that is how it shows in the diagram i downloaded from NH website. something chapped that cause the end of the rod to fall away from back of the piston and it is bound up. That's is guess but reliving the pressure and arm not coming down corroborates that .

 

[sandman2234]

The tractor has been sitting all night with rear end lifted in the air, being supported by jackstands under lift arms. No drop at all!
David from jax

 

[JC-jetro]

The tractor has been sitting all night with rear end lifted in the air, being supported by jackstands under lift arms. No drop at all!
David from jax

it must be a mechanical interface/binding. Need to push the piston out but how? I wished yours had a cylinder sleeve like almost all of them I saw in 1000 series. That might force you to remove all the top assembly to have access to the ram rod, Pivot arm and a way to push piston out from the back. Nasty situation say the least!
what do ya'll think. How can you pull the piston out if you can't push it out from behind.