Ford 1700 3 pt lift problem

   / Ford 1700 3 pt lift problem #81  
My first tractor was a brand new 1982 Ford 1700 4WD. One day it started this "jerking" motion when I raised the rear blade. I opened the raise/lower valve wide open. Raised/lowered the rear blade MANY times. For whatever reason - the jerking motion quit and never returned. I would guess there was air in the system or something got stuck or a bit of flotsam in the system got flushed out.
yup. going back to passing that dang kidney stone eh! I think that's a good possibility after all the work our friend has done.
 
   / Ford 1700 3 pt lift problem #82  
The pressure gauge was in the same place as when the pressure was adjusted up--the spot you recommended.

There is a relief valve on the loader.

I think I can remove the loader from the system. I will try that today. I have the bucket supported by blocks now.

Here's a photo of the oil--new and after maybe 1/2 hour of run time. The used oil is still translucent and there is nothing floating in it.
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   / Ford 1700 3 pt lift problem #83  

I checked the oil that you used. This is clearly not hydraulic oil meeting Ford 134. Did you actually use this oil in your transmission/hyd?
I hope you did not as again this is an engine oil. My engine oil looks dark on the right side but that is mixed with product of combustion. MY hyd oil looks like the one as far as color. It only looked milky with condensation and moisture for tractor being stored for about 4 months under a tarp

The one below is okay.
If you used this one for hyd then you are okay as it meets. M2C-134D which is NH equivalent oil.

JC,

When I looked at the bucket I did not notice hyd oil and just googled the brand name.
 
   / Ford 1700 3 pt lift problem #84  
I was able to cut both the power steering and the loader out of the system, and the pressure did not move off of zero and the 3-point did not move.

Do you have any idea why that oil should get so black with the little use it has had?

I have decided to trace the system from the pump forward. I think that the pump was putting out volume and pressure and for now I am assuming that is still the case. So I was looking at the cover relief valve. All the parts are there and seem to be in good condition. The only irregularity I see is the hole that the oil would have to pass through if the valve is relieving-dumping to keep the pressure from exceeding the 2100 psi. The oil should push against the poppet and go out through the holes in the side of the seat. What keeps the oil from pushing the seat out of the way instead?


It would be good to be able to run the loader and power steering and not the 3-point. I don't think there is a simple way to do that. But it would eliminate all the stuff under the seat. Maybe I could use that block to try something.

I wonder what that set screw on the side of the relief valve is for. It's called the "Taper Spring Plug."

Here's a photo of the ragged hole.

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   / Ford 1700 3 pt lift problem #85  
I was able to cut both the power steering and the loader out of the system, and the pressure did not move off of zero and the 3-point did not move.
Ok. we hold the assumption that pump is pumping and making pressure. The only route that oil has is to the relief device. Two things can happen there. The flow is routed to the spool and at the stiffness (pressure associated with that) of the spring ,adjustable. if pressure developed is above the spring stiffness then it has to dump. I don't thing there is anything in between,


Do you have any idea why that oil should get so black with the little use it has had?

I have no idea unless it pick up muck from diffy. Does the dipstick shows the same color? there is no crossc connection between hyd fluid and engine oil. if the main oil seal is leaking by from the engine then it goes to clutch housing that easily can be verified by taking rubber cover off of tranny. If the seal on the transmission shaft leaks by again it goes in to tranny. Just can see any scenario that engine oil can get mixed with hyd oil. The black color on engine oil is primarily due to product of combustion. That has me stomped.

I have decided to trace the system from the pump forward. I think that the pump was putting out volume and pressure and for now I am assuming that is still the case. So I was looking at the cover relief valve. All the parts are there and seem to be in good condition. The only irregularity I see is the hole that the oil would have to pass through if the valve is relieving-dumping to keep the pressure from exceeding the 2100 psi. The oil should push against the poppet and go out through the holes in the side of the seat. What keeps the oil from pushing the seat out of the way instead?

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Now this is not my picture. One of the guys posted as he was having issue and I was trying to help. I have not had a need to completely disassemble mine to get a closer observation. How it should work is spring is held against the poppet valve (cone shape) and then flat thick washer with cyllindrical piece at one side. The OD of that is the a bit smaller than ID of the spring. The OD of the valve (conical) is bigger that ID of the seat (with 4 holes). The seat is actually is in contact with the inner body of the relief device ( where you show a non-concentric hole on your picture), The valve seat has nowhere to go so oil can not move that as you were questioning. The poppet rides in and out of the seat (as they call it) but where the conical valve (the cone part of it) is against the gouged out hole. That is really the seat in my opinion. I think it has to be perfectly round as yours is not.

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I think that is where it is leaking by perhaps without even lifting the poppet. so in that fix, you have flow but all is goes passed spring without lifting it. That is exactly why that you reported with the lift cylinder head removed you could see and hear splash of oil in the diffy housing. That's my story and I am sticking to it :D . I think on over pressure this thing chatterd for a long time and wallowed up the roound hole.


It would be good to be able to run the loader and power steering and not the 3-point. I don't think there is a simple way to do that. But it would eliminate all the stuff under the seat. Maybe I could use that block to try something.

If you are not using 3 point, raising or lowering then pretty much 3 point is not used. I don't believe you can isolate the flow from relief to lift spool in anyway.

I wonder what that set screw on the side of the relief valve is for. It's called the "Taper Spring Plug."

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are you talking about a set screw above the banjo and top bolt of relief device? if so , I don't know any purpose for it , may be it was used to matching the port in to the valve body. I could not find a designation for "taper spring plug" on my manual. I don't reckon it does anything.

Here's a photo of the ragged hole.

Yup , see it . I think it is jacked up. The the taped part of the poppet will have a round circumference at any depth since id it symmetric and conical. Tat has to mate with a perfectly round hole to make a tight seal and i don't believe that's happening. Now how do you correct it. Either you replace that part ,basically body of the relief (hard to source) or a long shot would be to machine that hole round and perfectly concentric in regards to taper of the poppet. if that can successfully done then spring tension can be increased for material lost (removed). that is a difficult task. I wished the mating seat was replaceable. On a lot of valves for HVAC application the seat can be renewed but not here.
 
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   / Ford 1700 3 pt lift problem #86  
Maybe the wallowed-out hole would allow oil to go around the seat or push it and the seat back into the spring with excessive pressure. I don't think the wallowed-out hole ever contacts the poppet. That seat has a tapered hole the fits the poppet--both of which are still in good condition.

If it was a bad enough leak to turn the hyd oil that dark, I would think it would show in the engine oil level and the hyd dip stick. Maybe the oil is black because it is getting hot from being forced through small orifices.

If the 3-point control valve is always dumping oil except when it is raising something, then why is there enough pressure to run the loader or power steering?
 
   / Ford 1700 3 pt lift problem #87  
Maybe the wallowed-out hole would allow oil to go around the seat or push it and the seat back into the spring with excessive pressure. I don't think the wallowed-out hole ever contacts the poppet. That seat has a tapered hole the fits the poppet--both of which are still in good condition.
That is what I said n my previous post. I do not remember to see if the seat has a conical shape machining to match the properly fit he conical poppet? can you verify that. Whatever damage the hole must be from repeated strike. Any time you raise the 3 point beyond the highest point you would have the poppet striking the seat or top of it the oil inlet hole. I wondered where the chars of metal ended up after coming off the metal.
If it was a bad enough leak to turn the hyd oil that dark, I would think it would show in the engine oil level and the hyd dip stick. Maybe the oil is black because it is getting hot from being forced through small orifices.

Pleae re read my comment from previous post. There is NO PHYSICAL connection between crank case and transmission at all. clutch housing is where they both connect too. Either seal laeaking has to show up in the tranny by removing the rubber cover.
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If the 3-point control valve is always dumping oil except when it is raising something, then why is there enough pressure to run the loader or power steering?

How could it not be. Once the 3 point lift is at it's desired poiint then you can supply flow. Where should the flow go? You might need to research " Open Center" hydraulic system.


You have and AUX block for the loader, the priority is give to 3 point and then loader and lastly power steering. if tractor is on and you do not manipulate loader control, steering and 3 point then %100 of flow is diverted to tank. Pressure and flow are two different thing. You can have trapped pressure in a cylinder, like the loader. In that example you have pressure but no flow. put a bucket a dirt and raise it up, turn off tractor and with no flow you still have pressure of bucket weight transmitted too fluid in the cylinder causing pressure but not flow.
 
   / Ford 1700 3 pt lift problem #88  
I'm sorry, I must have misunderstood. The seat does have a conical hole for the poppet to fit into.

I think my loader connection must block that plug in the photos above. Are you looking at the clutch through that hole? Is there a release bearing grease zerk? I was thinking backwards--if the pump seal was badly leaking then the crankcase would fill up.

Now that I have the relief valve and the block off, I can understand it better. There are 3 holes in the relief valve and the cover, but only two come through from the block. So oil comes into the relief valve through the cover and the block (where the power steering and loader oil gets routed to the other block). But there is no outlet back through the block into the cover. The only way for oil to leave the relief valve is through the poppet and seat. There must a T in the cover so that oil can get to the control valve. But my picture shows the oil flowing through the relief valve and into the control valve.

It turns out that the banjo bolt is 1/2 inch pipe thread. So it was easy to test the loader without anything else being hooked up. And the loader worked fine. I couldn't believe it--I thought it would be some metric bolt size that I was going to try to adapt to 3/8 pipe. I was careful. It threaded in mostly by hand.
 
   / Ford 1700 3 pt lift problem #89  
I'm sorry, I must have misunderstood. The seat does have a conical hole for the poppet to fit into.

Ok Good. That makes sense.

I think my loader connection must block that plug in the photos above. Are you looking at the clutch through that hole? Is there a release bearing grease zerk? I was thinking backwards--if the pump seal was badly leaking then the crankcase would fill up.

Yes I know the loader mount covers the plug. That plug is outstanding design. I wished more manufacturer duplicated that or at least put a peep hole to send a camera in. in a matter of two minutes, I can measure the thickness of my clutch disk, verify operation of release bearing, see if the release bearing touches the fingers (three in all) of the clutch spring plate and any seal leaking on the transmission or engine. No, you will never see grease zerk on the release bearing as there is no access to grease it up without a tractor split. All the release bearing that I have seen are per-greased for it's life.

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My clutch is OEM one and after 40 years and 1300 hrs I still have %90 of original thickness left. That is impressive for an old rig.


Now that I have the relief valve and the block off, I can understand it better. There are 3 holes in the relief valve and the cover, but only two come through from the block. So oil comes into the relief valve through the cover and the block (where the power steering and loader oil gets routed to the other block). But there is no outlet back through the block into the cover. The only way for oil to leave the relief valve is through the poppet and seat. There must a T in the cover so that oil can get to the control valve. But my picture shows the oil flowing through the relief valve and into the control valve.

Yes. My understanding is that the oil comes from block and enters the relief and at that point normally routed too 3-point from one hole and the other hole routes the over-pressure flow back to tank either thru spool valve or just an opening on the diffy cover. I have not opened the system that far.

It turns out that the banjo bolt is 1/2 inch pipe thread. So it was easy to test the loader without anything else being hooked up. And the loader worked fine. I couldn't believe it--I thought it would be some metric bolt size that I was going to try to adapt to 3/8 pipe. I was careful. It threaded in mostly by hand.

Ok. That's great. so are we done with this project? does the 3-point work? I am glad you were able to resurrect the old pump.
 
   / Ford 1700 3 pt lift problem #90  
Well, I learned that the loader and pump seem to work normally. But that was without the 3-point plumbed in. Everything was bypassed--I went directly from the pump to the loader. I really appreciate all your help with this. And if you want to take a break from it, I know the feeling. Thanks. I'm still hoping that the relief valve is the cause of all the other problems.
 
 
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