[bbpitts]

I have a 2000 4020ps that I was a good running tractor with a strong Linamar/onan. Over the years it wore out the TCV linkage. The linkage is pretty much unreachable due to the power steering. The linkage finality got so it bad to be changed and in the mean time one of the hoses started leaking. Time to fix it. This tractor has center lift, front and rear hyd pto, and power steering.I believe the tractor has 16 hoses jammed underneath and in the tower it looks like a bowl of spaghetti and one hose was leaking so everything was covered in oil and it was hard to see which one it was.
It was ps hose with a pin hole blowing oil and two other hoses seeping enough to drip, I wound up replacing 7 hoses.
All hoses are a different length so you can't put them on wrong or so I thought. I mistakenly connected the power in to the return side of the the power steering orbital valve which connected the pressure side to the tractor return. When I started the tractor, the pump pressure blew a hole in a tractor return hose, about a gallon of oil all over me and the garage.
After I put it back together correctly, everything works and doesn't leak except the power steering. It steers but there is no power. did my mistake blow out that steering valve? The parts book shows a pressure relief for that valve.
I can not find literature on later 4020ps, so any help would be appreciated.
Thanks Bill

 

[bobneumann]

I don't know if anyone can say for certain, I know I can't. But based simply on the facts you've presented, that it used to work, then after being hooked up backwards it quit working, my guess would be that there has been some internal damage to the PS valve.

I'd guess that it's probably just some seals or something that a rebuild would fix.

You're correct that it has pressure relief built into it, but your scenario applied pressure to the outside of the relief valve, so it wouldn't have helped in your situation.

Sorry.

Bob

 

[Lionel]

Hmm, sounds difficult.

Firstly, have you tested to see if you're getting pressure or flow to the power steering cylinder? Has the system been bled to remove air? Have you raised the from of the tractor and turned the steering left to right stops, back and forth to remove any air trapped in the system?

I know you say, it's all connected correctly, But, on the steering pump, aren't all connections kind of side by side? Potentially 2 might be in the wrong location? (I assume, when discussing steering pump, the link below is somewhat similar to what we are discussing?
https://www.casecoltingersoll.com/d...ls/Parker 2753 HGF Power Steering service.pdf

The steering pump is a fairly intricate little piece of equipment,, I think I'd be talking with manufacturers, explaining what was done, and what the result is,, they might be able to point something out,,

Start with bleeding the system, and cross fingers.

 

[bbpitts]

Thank you for your answers. The reservoir is full, let it it run long enough that most of the air should be gone enough to see a difference.
I put a pressure gauge in the line from the regulator to the ps valve in port, registers 500lb at idle and 700 at half throttle, so the orbital valve is getting pressure. Rev-ed up, the main pump is putting out about 3000 lb to the regulator.
I have had three leaking hose problems so that means of had to drain that hyd system three times, looks like I'm going to drain it again. Don't think you can get the steering valve out with removing the tank.
Lionel, I missed that manual on power steering, thank you for sending link. Since it says Ingersoll on the pages, I assume that they used a Parker2753 HGF Valve. I will look for a kit.
I'm open to-any other ideas,
Thanks Bill

 

[bobneumann]

Thank you for your answers. The reservoir is full, let it it run long enough that most of the air should be gone enough to see a difference.
I put a pressure gauge in the line from the regulator to the ps valve in port, registers 500lb at idle and 700 at half throttle, so the orbital valve is getting pressure. Rev-ed up, the main pump is putting out about 3000 lb to the regulator.
I have had three leaking hose problems so that means of had to drain that hyd system three times, looks like I'm going to drain it again. Don't think you can get the steering valve out with removing the tank.
Lionel, I missed that manual on power steering, thank you for sending link. Since it says Ingersoll on the pages, I assume that they used a Parker2753 HGF Valve. I will look for a kit.
I'm open to-any other ideas,
Thanks Bill

You may want to have a look at it before you buy anything. I'm not certain that Parker was the only unit they ever used.

Bob

 

[bhildret]

All 3000/3100/4000/4100/4200/6000/7000 Ingersolls with power steering use the Parker HGF steering controller.

The early production 648's used a different system entirely, while late production 648's also used the HGF's

Brian

 

[bobneumann]

Thank you Brian. Very helpful. I love it when someone weighs in who actually knows what they're talking about!

Bob

 

[bbpitts]

Using the link that Lionel sent me, I made sure all the PS hoses went to the correct ports on the orbital valve.
I even checked Parker HGF valves on line and the diagrams were the same.
In the past the engine always started and ran fine and I didn't do anything to it.
The the engine will make about a half revolution and then stop suddenly, like trying to start a car in gear. I think the engine might be dead headed and the hydraulics are stopping it.
Case tractors will steer with the engine off. Now if you turn the wheel right, the tires turn right but if you turn the wheel left, nothing happens and the tire are locked. If you want to move the tire by hand to steer, you have loosen a hyd hose to the cylinder to relieve pressure.
Something is still wrong or I blew the valve on the first incorrect hookup.
The third time I put it together everything worked but the power steering, so it has to be something in the ps system.
Tomorrow I will drain and take it apart the fifth time and this time I'll remove the steering valve.
Thanks Bill

 

[bobneumann]

I hate it for you, but it does seem like something must be messed up inside that valve. If nothing else the relief on a trip when you start the engine and allow the fluid to bypass the valve and go out the relief. So either the relief ball is stuck hard in the passage from having been pushed the wrong direction, or the oil isn't even reaching the relief valve.

But no matter what it does seem like you're going to have to crack that valve open.
Bob

 

[Lionel]

Using the link that Lionel sent me, I made sure all the PS hoses went to the correct ports on the orbital valve.
I even checked Parker HGF valves on line and the diagrams were the same.
In the past the engine always started and ran fine and I didn't do anything to it.
The the engine will make about a half revolution and then stop suddenly, like trying to start a car in gear. I think the engine might be dead headed and the hydraulics are stopping it.
Case tractors will steer with the engine off. Now if you turn the wheel right, the tires turn right but if you turn the wheel left, nothing happens and the tire are locked. If you want to move the tire by hand to steer, you have loosen a hyd hose to the cylinder to relieve pressure.
Something is still wrong or I blew the valve on the first incorrect hookup.
The third time I put it together everything worked but the power steering, so it has to be something in the ps system.
Tomorrow I will drain and take it apart the fifth time and this time I'll remove the steering valve.
Thanks Bill

Just a quick question before tearing the thing apart because the engine appears to be "dead headed".

Do you have a rear PTO valve, if so, is it in the neutral position?
Here's a bit of a story, 3 years ago, xmas time, I go home to use my 446 for snow removal. I finally got it to start, but I just couldn't get RPM's out of it. I had to boost and really work to get it started in the first place.. Anyways, thinking there's a carb issue, spent a couple of hours tearing the carb apart, checking linkages ext, put things back together, managed to start it, and same thing. Called boomer to bounce things off of,, he suggested a bunch of things, and now I'm getting dishearted because this 446 has seen a lot of $$$ go into it. Decided to try starting it again,, same thing. Whiles it's running, I'm now contemplating life,, just thinking, and I hear this little whine, from the rear of the tractor. I check, everything seems okay with my PTO,, but decided, what the heck, give it a flick and see if noise goes away,, it did, and now, my motor picks up and I've got RPM's.. Who hoo, my wife had gone by, "partially engaged the PTO" and that was what the problem was. My PTO valve handle is now safety tied,, still married, and still loving my wife,,

Anyways, if you have one,, check closely,,,and be sure.

As a test, not pretty, but you could disconnect one line going to the steering cylinder, stick it into a bucket,, "specially the one that you have to relieve pressure on",, Use one of the old hoses you've replaced, and stick that one onto the cylinder, with other end into same bucket,, does your motor turn over, (don't start it), which one squirts oil whiles the tractor is sitting there, idling? "Not touching the steering wheel",, nothing should be coming out of those hoses, I think,,

Anyone else want to comment on this?

 

[bobneumann]

Just a quick question before tearing the thing apart because the engine appears to be "dead headed".

Do you have a rear PTO valve, if so, is it in the neutral position?
Here's a bit of a story, 3 years ago, xmas time, I go home to use my 446 for snow removal. I finally got it to start, but I just couldn't get RPM's out of it. I had to boost and really work to get it started in the first place.. Anyways, thinking there's a carb issue, spent a couple of hours tearing the carb apart, checking linkages ext, put things back together, managed to start it, and same thing. Called boomer to bounce things off of,, he suggested a bunch of things, and now I'm getting dishearted because this 446 has seen a lot of $$$ go into it. Decided to try starting it again,, same thing. Whiles it's running, I'm now contemplating life,, just thinking, and I hear this little whine, from the rear of the tractor. I check, everything seems okay with my PTO,, but decided, what the heck, give it a flick and see if noise goes away,, it did, and now, my motor picks up and I've got RPM's.. Who hoo, my wife had gone by, "partially engaged the PTO" and that was what the problem was. My PTO valve handle is now safety tied,, still married, and still loving my wife,,

Anyways, if you have one,, check closely,,,and be sure.

As a test, not pretty, but you could disconnect one line going to the steering cylinder, stick it into a bucket,, "specially the one that you have to relieve pressure on",, Use one of the old hoses you've replaced, and stick that one onto the cylinder, with other end into same bucket,, does your motor turn over, (don't start it), which one squirts oil whiles the tractor is sitting there, idling? "Not touching the steering wheel",, nothing should be coming out of those hoses, I think,,

Anyone else want to comment on this?

If the valve has internal issues then that would be the reason that fluid is diverting through one or more of those hoses without any steering input.

Bob

 

[bbpitts]

Thanks again,
I will check the pto but my safety switches,neutral and pto are still working, won't crank unless there in neutral. The hi/lo gear selector is in neutral also so I wouldn't get run over.
Tomorrow I will disconnect the hose from the regulator that goes to the in port on the ps and see if that makes a difference. I will also disconnect the steering cylinder and see what happens, That should be a mess, I've already used 3 bags of oil dry.
Don't know if I'm tenacious or too dumb to quit.

 

[Timj]

I agree with Lionel, before you tear it apart again. Start checking some other things.

The power steering is powered through a diverter valve. Only a couple of gallons per minute are broke off from the flow of the full pump flow. Even if the power steering is totally blocked/deadheaded it shouldn't snub the engine. The extra flow should just go through the main hydraulic circuit. You mentioned in an earlier post that you had 3000psi at the regulator, are you referring to the diverter valve? Even at full throttle I don't believe you should get that high of pressure unless something in the main circuit is blocked or under load.

 

[bobneumann]

I agree with Lionel, before you tear it apart again. Start checking some other things.

The power steering is powered through a diverter valve. Only a couple of gallons per minute are broke off from the flow of the full pump flow. Even if the power steering is totally blocked/deadheaded it shouldn't snub the engine. The extra flow should just go through the main hydraulic circuit. You mentioned in an earlier post that you had 3000psi at the regulator, are you referring to the diverter valve? Even at full throttle I don't believe you should get that high of pressure unless something in the main circuit is blocked or under load.

The diverter (proportioning) valve is not like a tee. It will divert that 2gpm (or whatever) to the power steering "no matter what". There's no "overflow" from there, that flow is absolute. If you dead-head the line coming out of there, it will absolutely go up to 3000psi or more, and it will absolutely deadhead the pump. It's kind of amazing that it can work that way, but it does.

Bob

 

[Timj]

So what you are saying is the diverter valve is shutting off the main, open system and sending the entire flow and pressure into the steering?

 

[bobneumann]

So what you are saying is the diverter valve is shutting off the main, open system and sending the entire flow and pressure into the steering?

Yes. The diverter receives all the flow from the pump. And it will provide "back pressure" to the pump as much as necessary to send its 1.6 or whatever GPM out that power steering port. Up to the point of stopping all flow. If nothing can flow out that port then nothing can flow out of the diverter at all. If that were not the case, then you could never have higher pressure on the power steering port then you could have on the main port. But that's precisely the capability that a diverter like this provides. It's a strictly enforced proportional flow divider. The power steering port always gets, say, 15%. So if the power steering port has zero flow, then the TCV port gets 85% of zero.

That amazing thing about that is that you can have a 3000 PSI component running from one of the diverter ports. And have only a 300 PSI running from the other diverter port. And they will each get their relative pressure.

I researched it because I considered using a diverter valve like it to power my loader. If I would have gone that route I could have had 3,000 PSI diverted to the loader, while the TCV only tripped at 1900 or whatever.

Bob

 

[bobneumann]

Now that I think about it, I may be saying it wrong. I think that it's not actually a proportional valve, if I remember right, it's actually a priority valve. Which is the same ultimate result, but slightly different logic.

Let's put it this way. "The travel control valve gets whatever is left over AFTER the power steering port has gotten its 1.6 GPM." Until the power steering port has gotten its 1.6 GPM, the TCV port gets nothing. So if it can't send any flow to the power steering port, then it will never have any "left over" to send to the TCV port.

As I say, it's the same end result, but it's a slightly different way of thinking about it.

Bob

 

[Timj]

If this is truly how this works, I would have thought they would have used hydraulic hoses for the power steering rated for more than 3000psi. Also with this situation you would have thought there would have been a system relief valve put before the diverter valve to protect the pump and system.
I don't believe that there's been major real world trouble with the PS system, if there was we would be seeing blown hoses and blown up pumps any time there was a problem with the valve or the steering. Also, any steering issue would impact tractor performance.

Sorry to kinda hijack your thread, bbpitts, I guess you're back to taking the power steering out.

 

[bobneumann]

You're right. The power steering valve has an internal pressure relief that's only set... In the mid 300s? So unless there's an internal problem with the power steering valve, it'll never cause difficulties with the rest of the tractor. But it seems like in this case the power steering valve may be deadheaded, and the pressure relief isn't tripping.

I'm not making the case that there MUST be something wrong with this power steering valve. I'm no more certain what's actually going on than anyone else. But I am saying that if the power steering valve were deadheaded, then it would ultimately deadhead the pump itself.

Bbpitts, while you're checking out the power steering valve, you might also check the pressure relief assembly to make sure that the ball has not somehow gotten stuck in its channel.

Bob

 

[bbpitts]

Once again thank everyone who replied because I am stumped.
To clarify pressure, the 3000 lb was at the screw at bottom of the TCV and that was a 20 hp onan almost dead headed. The 500 to 700 lbs was an inline gauge I put in the PS hose coming out of the regulator/diverter/priority valve when the hoses were connected incorrectly. Case calls this valve a regulator in the parts book, it is diverter that takes priority flow to the PS.As long as we all talking about the same thing.
The way it is plumbed, a 3/4 hose comes off the pump directly to this valve, on one side a 1/4 hose goes to the PS in, on the other side a 3/4 hose goes to the hyd pto than to the in port on the TCV.
Until I connected the hoses per the picture in the manual, there absolutely no problem with the engine turning over and starting.
It is impossible to look up in there and see the marking on the valve. The one port is offset, using that as a reference I thought I got the right ports.
My memory thinks the left /right hoses to the cylinder went to the two ports on the left side of the tractor, the manual picture shows them going to forward facing ports. I normally make notes/drawings or take a picture with the phone, I know how good my memory is. but when I did it my way the engine started of course it still didn't work.
Please keep checking with ideas until I get this fixed. My wife just got a new hip and I'm going to be busy for a couple days until I can get back to it. It is a wonder what they can change, I want to jackup the steering wheel and put a new tractor under it.
Thanks again Bill