Case international 385 hydraulic issues

[Loganchurch]

Hey guys I have a case international 385 that came into the shop for shearing the key on a new hydraulic pump. I removed the mcv and found the pump drive gear nut to be loose. The aftermarket company warrantied the pump and I installed it and started checking hyd pressures at the steering line. I found it to be making too much pressure and flow. Thought the pump was just new and would break in. Ran the unit for about an hour and started loosing hyd pressure to the point it would not turn at idle. Disassembled the unit again and found the pump housing to be split on the driven gear side. Ordered a new oem pump and compared the 2 and found that the broken pump was a higher volume pump. So my question is how likely is it that I have another problem in the hydraulic system or would the increased pressure and flow cause the pump the fail since the system is not designed for that amount of pressure

 

[JimB2]

Does the 385 have a loader on it? Do you have any manuals that describe the hydraulic system?
The main relief valve in the bottom right of MCV should open at about 2500 PSI to protect the pump from dead heading.
The priority valve in bottom of MCV should split the hydraulic flow 3 GPM to PS, Oil Cooler, T/A or FWD/REV and PTO and remainder to 3 PT and remotes. There was an option for tractors with a loader to have a 17 GPM pump.
I can copy and paste some pages from my CIH manual about hydraulic flow diagrams to this post.

 

[Loganchurch]

Does the 385 have a loader on it? Do you have any manuals that describe the hydraulic system?
The main relief valve in the bottom right of MCV should open at about 2500 PSI to protect the pump from dead heading.
The priority valve in bottom of MCV should split the hydraulic flow 3 GPM to PS, Oil Cooler, T/A or FWD/REV and PTO and remainder to 3 PT and remotes. There was an option for tractors with a loader to have a 17 GPM pump.
I can copy and paste some pages from my CIH manual about hydraulic flow diagrams to this post.

Yes it does have a loader. When checking hyd pressure by the book it said max flow and psi should be 2600. I’ve pulled the flow control valve and it fits tight in the bore and shows little to no signs of any wear. I measured the spring and it was within spec. Also replaced the relief valve. I’m leaning towards too much pump for the tractor to flow properly or a problem with the mcv itself. I also had to replace the steering cylinder because the piston slid on the shaft blocking one of the holes. After running the tractor it developed a leak from the fitting on the left hand side of the steering cylinder as well which is tight and I replaced the o-ring on it when replacing the cylinder. I have the book for the tractor but I’m still scratching my head

 

[Loganchurch]

Yes it does have a loader. When checking hyd pressure by the book it said max flow and psi should be 2600. I’ve pulled the flow control valve and it fits tight in the bore and shows little to no signs of any wear. I measured the spring and it was within spec. Also replaced the relief valve. I’m leaning towards too much pump for the tractor to flow properly or a problem with the mcv itself. I also had to replace the steering cylinder because the piston slid on the shaft blocking one of the holes. After running the tractor it developed a leak from the fitting on the left hand side of the steering cylinder as well which is tight and I replaced the o-ring on it when replacing the cylinder. I have the book for the tractor but I’m still scratching my head

Will also recheck pressures and flow once the new pump is on

 

[JimB2]

Is the loader still connected? Does the loader have it's own set of valves? Do the valves have a pressure relief valve?
If loader has it's own set of hydraulic valves make sure that with the valves in Neutral that the hydraulic oil flows in the IN port and out the OUT port and back to the trans/diff hydraulic reservoir properly especially if there is no inbuilt relief valve on the loader valves.
My brother has 5 of these IH/CIH series tractors, the CIH 495 had a 2250 loader on it and it had the regular 10 GPM pump and later he bought a CIH 3230 and it has a 17 GPM pump on it and we moved the 2250 from the 495 to the 3230 and the 3230 lifts the loader much quicker with the 17 GPM pump. I thought with the 17 GPM pump the hydraulic filter canister was larger than the one used on the 10 GPM pump but looking at Caseih.com parts there didn't appear to be any p/n differences.
Good Luck

 

[Loganchurch]

Update. I got the new oem pump on and connected a flow meter to the steering supply pipe fitting on the mcv. The unit is flowing 5gpm and when closing the load valve the pressure goes to over 3000 psi with no changes in flow rate. I have replaced the relief in the bottom of the mcv. The book does not show anything about how to diagnose too much flow and pressure. Just shows what to do when pressure is low

 

[JimB2]

Hi see photo below.
If your 385 doesn't have the FWD/REV Shuttle shift then the upper left hydraulic line on the MCV goes to the oil cooler in front of the rad.
The Power Steering relief valve on mid left of MCV is supposed to be set at 1500 PSI and when it trips the excess oil goes to the oil cooler.
The normal oil cooler flow was 3 Imperial GPM with the 10 Imp GPM pump but looking at Caseih.com parts all replacement pumps are about 15 GPM so the PS and oil cooler flow would be around the 5 GPM that you measured.
Check flow to oil cooler and then inspect PS relief valve and Oil cooler bypass valve. The usual failure of the Oil Cooler Bypass valve is to let all the flow go to the oil cooler and you loose pressure to PTO valve.
I would be very careful testing the pressures and only run tractor at idle as 3000 PSI could do damage to hydraulic lines and the new pump.
On the PS, when you turn the steering wheel to the limit in either direction, you should hear the PS relief valve whine.

 

[Loganchurch]

Oka

Hi see photo below.
If your 385 doesn't have the FWD/REV Shuttle shift then the upper left hydraulic line on the MCV goes to the oil cooler in front of the rad.
The Power Steering relief valve on mid left of MCV is supposed to be set at 1500 PSI and when it trips the excess oil goes to the oil cooler.
The normal oil cooler flow was 3 Imperial GPM with the 10 Imp GPM pump but looking at Caseih.com parts all replacement pumps are about 15 GPM so the PS and oil cooler flow would be around the 5 GPM that you measured.
Check flow to oil cooler and then inspect PS relief valve and Oil cooler bypass valve. The usual failure of the Oil Cooler Bypass valve is to let all the flow go to the oil cooler and you loose pressure to PTO valve.
I would be very careful testing the pressures and only run tractor at idle as 3000 PSI could do damage to hydraulic lines and the new pump.
On the PS, when you turn the steering wheel to the limit in either direction, you should hear the PS relief valve whine.


Okay so on this unit there is no steering relief valve in the side of the mcv just the system pressure relief valve on the bottom right of the mcv.

 

[Loganchurch]

Okay so I plumbed the flow meter into the hitch supply port and found the unit to be hitting the relief at 2500 psi as specified. I then plumbed a gauge into the left hand side steering line and checked pressure there and I’m getting the 3000 psi when turning the wheel. I’m going to adjust the steering relief on the hand pump and go from there

 

[JimB2]

Oka

I learned something today, you are correct, I went and looked in my CIH 85 Series Service manual and no separate PS relief valve. The MBAs must have been happy with CIH engineers saving a few cents. I never noticed the lack of PS relief valve on the MCV on my brother's CIH 495 and 3230 and we had the rear axles off both and to remove the left rear axle you have to remove a hydraulic line off the rear of the MCV. In my manual the PS flow should be 2.6 to 3.1 GPM @ 1600 PSI and full system pressure 2500-2600 PSI, so the new pump on your 385 is overachieving but the CIH Service Manual was probably referring to the original 10 GPM pump.
If you dead head a remote, do you hear the main relief valve squeal?

 

[Loganchurch]

I learned something today, you are correct, I went and looked in my CIH 85 Series Service manual and no separate PS relief valve. The MBAs must have been happy with CIH engineers saving a few cents. I never noticed the lack of PS relief valve on the MCV on my brother's CIH 495 and 3230 and we had the rear axles off both and to remove the left rear axle you have to remove a hydraulic line off the rear of the MCV. In my manual the PS flow should be 2.6 to 3.1 GPM @ 1600 PSI and full system pressure 2500-2600 PSI, so the new pump on your 385 is overachieving but the CIH Service Manual was probably referring to the original 10 GPM pump.
If you dead head a remote, do you hear the main relief valve squeal?

This unit is not equipped with remote valves. In my book it shows an adjustable relief valve on the top of the steering hand pump. This hand pump does not have a relief valve on it but has been replaced. I’m thinking the lack of pressure regulation in the steering system is what is causing my pump failure

 

[JimB2]

You are correct about PS hand pump having a 2150 PSI relief valve built into it. I read the section 29-30 in my CIH 85 Series Service manual that showed item #5 - relief valve in Figure 35 and how to test and adjust it to 2150 PSI. That explains that is the reason on my brother's CIH 495 and 3230 when I hear the PS relief valve squealing the sound appears to be coming from under the dash. Well I have learned a lot in the last couple days as I had just thought CIH 85, 95, 32XX, 42XX Series tractors had same PS as the earlier IH 54,74,84 Series tractors.
So your only solution is to be really careful with PS or find and inline relief valve like IH 384 used or replace the steering hand pump?