Case 1030 Hydraulic Pressure-Question for John Saeli or others

DRussell

Well-known Member
Is 2400 psi at idle with cold oil (55-60 degrees) too high, as in that high of pressure will damage components?

The story. Back in 2022 the PTO clutch went out and was replaced by the local Case dealer. They tried to clean it up inside as best they could from the clutch fibers getting in things, but afterwards, the 3 point did not work right. When it was cold, it wouldn't raise, after the oil warmed up it would raise. I lived with it like that for a while because the tractor doesn't get a lot of use. Then, this winter with the snow blower on the 3 point wouldn't raise it, either warm or cold.

A local mechanic came over and put a hydraulic gauge in the remotes and it was only making about 200 psi. He then put a flow meter on it and the pump easily produced 15 gpm at 2000 psi at a bit over idle speed.

So, we tore into the auxiliary valve and put essentially all new relief valve parts in it. I say essentially, as the relief valve sleeve is a pressed in fit and appeared to be in good shape with no scoring on it to the touch so we didn't replace it. We replaced the piston, piston assembly, the main spring and orings associated with the relief valve. We also replaced the orings and gaskets under each side head and the nylon washer that seals the valve to the tractor.

We did identify a possible issue with the piston assembly for the relief valve as there were a couple shiny spots on it like it was rubbing on one side more than the rest. We also identified an issue with the main relief valve spring as it was measuring 20-25 thousands short compared to a new spring. There were 6 shims under the cap on the relief valve and we left all 6 shims in per the advice of John Saeli, where we got the parts for the relief valve.

Anyway we got it back together tonight and tested it, with the cold oil (55-60 degrees), and it was making about 2400 psi of pressure at the remotes. The 3 point hitch also works normally as in it had no trouble raising the snow blower at idle speed.

So, my question is whether that high of pressure will damage components.
 
If the system is never taxed so that the relief valve is required to activate, it will never reach 2400psi. I have never seen, but have heard of the aluminum housing exploding. My advice is to remove enough shims to back the pressure down to 2000 - 2100.
 
If the system is never taxed so that the relief valve is required to activate, it will never reach 2400psi. I have never seen, but have heard of the aluminum housing exploding. My advice is to remove enough shims to back the pressure down to 2000 - 2100.
Is there a table that tells you how many thousands of shim equals "x" amount of pressure? The 6 shims are various sizes with the largest being 32 thousands. Some are 10, some are 15 and at least one is 20.

My manual simply says to add or remove shims until the proper pressure is reached and is silent with otherwise useful information like, "this shim size should equal this many pounds of pressure." Per the manual the "cracking" pressure of the relief valve on a 1030 with a hand pump is 1900-2050 psi.

As an aside, we did make a flat steel plate, as per the manual instructions, to block off the passage out of valve into the tractor and tried a hand pump to see what the cracking pressure was. We couldn't get anywhere near the pressure with a hand pump. With the low volume the hand pump could produce, the oil appeared to be getting past the internal spools about as fast as the hand pump could build pressure. We could only get a few hundred psi with the hand pump.
 
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Is there a table that tells you how many thousands of shim equals "x" amount of pressure? The 6 shims are various sizes with the largest being 32 thousands. Some are 10, some are 15 and at least one is 20.

My manual simply says to add or remove shims until the proper pressure is reached and is silent with otherwise useful information like, "this shim size should equal this many pounds of pressure." Per the manual the "cracking" pressure of the relief valve on a 1030 with a hand pump is 1900-2050 psi.

As an aside, we did make a flat steel plate, as per the manual instructions, to block off the passage out of valve into the tractor and tried a hand pump to see what the cracking pressure was. We couldn't get anywhere near the pressure with a hand pump. With the low volume the hand pump could produce, the oil appeared to be getting past the internal spools about as fast as the hand pump could build pressure. We could only get a few hundred psi with the hand pump.
I have never seen any kind of table. I'd take the .020" out and try that.
 
Looking back over previous posts and thought I'd put my 2 cents in, I'm not sure on the 30 series but the 70 series service manuals give the relief valve shim pack thickness for the various models, I have let some as high as 2200 without any complications, some of this new equipment takes more pressure than some of the older tractors have. I set my 830EH up high enough to operate a Hydro Swing mower.
 
Looking back over previous posts and thought I'd put my 2 cents in, I'm not sure on the 30 series but the 70 series service manuals give the relief valve shim pack thickness for the various models, I have let some as high as 2200 without any complications, some of this new equipment takes more pressure than some of the older tractors have. I set my 830EH up high enough to operate a Hydro Swing mower.
My 30 series service manual gives the shim pack as follows: For the 1030 use two .0149 shims and one .0201 shim. Then use as required: .0105 shim and .0329 shim.

It says to add or remove shims until the relief valve cracking pressure is reached.
 
1030 has a dry clutch so there is no way that stuff from the clutch could effect the hydraulic system. If you leave the hyd. pressure at 2400 PSI and run it to relief pressure you will eventually crack the front side of the remote valve. Did it on our 930 when we pushed the pressure up to lift a heavy ridge till cultivator.
 

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