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986 . New Hyd pump and relief value. Still no pressure


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We put a second hydraulic pump and relief value (the one under the fuel tank) in my 986 and still have low  pressure.  A friend who works at an IH dealer came out and checked it with his hydraulic tester.  He said the flow is good but when he applied pressure it drops off.  We tested both hydraulic hook ups.  He says he is stumped as to what could cause the issue and needs to think about it.  I was hoping someone here might have run across something similar and can help us narrow down the issue.

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Had the seal ring between top cover and rear frame blow  had flow but low pressure. To check remove top link cover and look if oil spraying out of left front wheretop and rear frame  meet when system is on pressure.

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6 hours ago, daveannette68 said:

We put a second hydraulic pump and relief value (the one under the fuel tank) in my 986 and still have low  pressure.  A friend who works at an IH dealer came out and checked it with his hydraulic tester.  He said the flow is good but when he applied pressure it drops off.  We tested both hydraulic hook ups.  He says he is stumped as to what could cause the issue and needs to think about it.  I was hoping someone here might have run across something similar and can help us narrow down the issue.

Look for leakage between the draft valve and the hitch cylinder housing.
 

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1 hour ago, 1586 Jeff said:

Okay, it took me half an hour to find my own topic about a very similar problem.  In my case it was the o-ring between the hitch pump cover and the rear end housing.

 

Thanks Jeff.  I took a look at #11 on the IH parts website.  We will look into it but I think I remember putting in that O-ring new when we put the pump on but worth re-checking.  That is what makes this hard to find.  I am sure there is a blown seal/o-ring someplace but figuring out where is painful.

 

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12 hours ago, Big Steve said:

Had the seal ring between top cover and rear frame blow  had flow but low pressure. To check remove top link cover and look if oil spraying out of left front wheretop and rear frame  meet when system is on pressure.

Thanks Big Steve.  I am headed out now to remove the center link house.  I am actually hoping to see oil spraying out so at least I know where the problem is.

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Big Steve...

I think you nailed it.  I took the top link cover off and tried to lift the front end up with the loader.  Hydraulic oil was spraying out of the space where the top link cover was.  It was coming out so fast I could not see where it was coming from but I will assume it is the seal you are referring to.  

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It would still be helpful to narrow it down a bit more. Run engine at idle and try again. If its coming from the hitch the top has to come off. If its coming from the seat support (the back corner where the linkage comes down) it doesn't.

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1 hour ago, snoshoe said:

It would still be helpful to narrow it down a bit more. Run engine at idle and try again. If its coming from the hitch the top has to come off. If its coming from the seat support (the back corner where the linkage comes down) it doesn't.

Thanks much Snoshoe.  I was just going to ask what the next step was and  what I need to take off to get to the bad seal.  I did not realize there are multiple seals it could be.  I am hoping it is the easy one to fix.  I will give it a try. 

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Hopefully this narrows the issue.  I kept the tractor as minimum throttle and this is what I saw.
With the 3-point push all the way forward, there is fluid spraying out of someplace on top right side. (picture #1)
With the 3 point pulled back, the arms go up and the fluid stops. (Picture #2)
With the 3 point pulled back and the hydraulics engaged, there is a river of fluid coming from the top right. (Picture #3)

With my luck, it is worst case and it needs the top pulled off.  Can that be done by just removing the fuel tank or does 20190407_151004.thumb.jpg.b4ba15fca4209f2576b75c96cf7151f3.jpg20190407_151047.thumb.jpg.8d67508decd8c26afaa57146a64fb87d.jpg20190407_151114.thumb.jpg.56694e81cfd8cf36616f4fe37d2a37f8.jpg cab need to come off?

I took a couple picture to show what I am trying to describe.

 

 

 

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Sorry I must be confusing you. I said seat support and that 86 doesn't have it. That block under the tank where you changed the relief valve. Pull the valve back out there should be an oring inside that seals that end of relief valve.

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The leak on my  tractor was on the front left corner this leak is coming from relief valve area or draft control valve. If it is the oring on relief valve only have to take fuel tank off  if draft control valve  top cover. If your fingers are good you may not have to remove tank. 

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7 minutes ago, snoshoe said:

Before commenting further I need to know how loader is hooked up. Is loader operated by tractor valves? By loader valve supplyed by tractor valve or power beyond?

Snoshoe - To answer your 2 questions. 

The picture with the river of hydraulic oil is under load(picture #3).  Picture #1 is no load and 3 point all the way down.  Picture 2 is no load but 3 point up a bit

The loader on the tractor is hooked up to the 2 tractor rear remotes and operated by the tractor valves and lever to the right of the seat.  There are no additional valves or pumps added for the loader.

If I understand what you are saying, there is an o-ring for the pressure relief value inside the block that may have failed?

What I am not understanding is why I have oil spraying out when the 3-point arms all all they way down(picture #1) and no load but when I pull the arm back a bit (still no load after arms raise), the oil stops spraying out until I put the hydraulics under load by pulling the hydraulic level to lift the loader.  Does that fit into you relief value o-ring theory or do you think I have more than one blown seal/o-ring?

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27 minutes ago, Big Steve said:

The leak on my  tractor was on the front left corner this leak is coming from relief valve area or draft control valve. If it is the oring on relief valve only have to take fuel tank off  if draft control valve  top cover. If your fingers are good you may not have to remove tank. 

Thanks big Steve.

I would LOVE to not have to remove the tank.  

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It would be normal for oil to come down there when ever the hydraulics are doing nothing. It is normal for it to stop when you raise the hitch because the oil is filling the cylinder. When the hitch stops raising the oil should start again. Your saying it doesn't? The oil has to go somewhere and all hitch components are in front of you in that hole. When you put the aux lever on demand the oil has to go out through the couplers, in your case making the loader move or go through or around the relief valve. A leak anywhere else shows up else where and that river you have stops.

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12 hours ago, snoshoe said:

I got to thinking bad cylinder seals on loader but you flowrated through couplers so loader was unhooked.

Yes, we unhooked the loader and tested the hydraulics through the same remotes the loader used.  We originally hoped it was bad cylinders on the loader but we hooked up the 9' discipline and it required almost full throttle to sing it out.

And Yes, I am also saying when the hitch stop raising the oil does not start spaying out again.

Tonight after work we are going to flow rate it again and take the pressure valve out again to see if the seals look damaged.

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Well you've handed me a pill I can't swallow much less digest. Everything hitch related except unloading valve is right there. The hitch is subject to the same relief valve as the aux. valves. As stated the oil has to be going somewhere. If its not here it has to be somewhere else. I have the same problem you do. Why closing an aux would set off relief and unloading valve don't.

Excess flow from the steering pump is available here with a check valve to prevent backflow. But I don't see how this enters into it.

Time for one of our many watchers to jump in here. I just can't figure where the oil is going with the unloading valve closed and the hitch not moving.

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On ‎4‎/‎7‎/‎2019 at 3:23 AM, Maynard said:

Look for leakage between the draft valve and the hitch cylinder housing.
 

X2

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