Case IH 275 Loader Control Valve

[Tractornewbie2]

Here is the original control valve. I just noticed that it has a PB port that was not used.

 

[LD1]

Any pictures of the new valve and where the hoses go?

Did you replace any hoses or change anything other than the valve?

How many hoses did you remove from the old valve?

What was the nature of failure of the old valve?

The N port is what is feeding the 3ph. Are the hoses correct. The hose that is hooked to the N port on the bottom of the tractor....what port on the valve is it hooked to?

The way the block is hooked up.....you really should be feeding the n port with a pb out of the new valve and add a tank return somewhere. Otherwise you may end up with the new valve split or leaking as well

 

[Tractornewbie2]

Diagram of Brand Control valve above is how it’s hooked up with with the P on inlet port and N on outlet port. I have tried to switch N and P and it does nothing. There are 6 hoses originally and none were changed. I did have to get 90 degree elbows for Inlet and Outlet connections.

The reason for the change was Top part of valve where handle attached was broke and made controls very sloppy and hard to use. I was starting to see slight leak as well.

 

[LD1]

The verbage in the manual about external service won't work for tractors equipped with 3ph control valve is concerning.

The diagram shows pump pressure should simply go in the new valve through it (since open center) and right back to n port which is the supply for 3ph.

It SHOULD have PB feeding the N. Whereas you are feeding it off the T of the new valve. But doing that only protects the loader valve and won't make any difference on 3ph performance.

Is the tractor acting like it's under load or deadheading hydraulics? If the 3ph won't raise when you raise the lever....what does it do (when it's should be raising) if you move the loader?

 

[LD1]

I ask those questions cause it almost acts like you got a valve that has the closed center plug in. Not allowing oil to pass through and on to the 3ph. Which is why I ask about if it sounds under load....cause closed center would force oil over relief.

And actuating a loader function would force oil out the tank port and make the 3ph operate.

So try that and report back

 

[Tractornewbie2]

Will do, thanks

 

[Tractornewbie2]

I did what you said and the 3pt hitch does seem to work when I move the loader.

 

[LD1]

Sounds like the new valve is setup for closed center.

I know it's a bit of work....but can you take off the Inlet and outlet hoses of the new valve. (the two hoses connecting it to the tractor) and blow compressed air in the inlet. It should free flow out the outlet. If it doesn't....the valve is closed center and that is your problem

 

[Tractornewbie2]

Wow, thank you so much. I will check it out and let you know.

 

[LD1]

Confirm that the Inlet to the loader is indeed coming from the P port on the tractor and that the Return is going back to the N port.

Take out the Hex plugI have labeled as possible CC plug. Take a pic and upload it. If it is more than a simple threaded plug....and has more on the end of it that block/modify the internal passages...then that is a CC plug, and is your problem. For the valve to be open center....that simply just needs to be a plug.

This is what that hex plug would look like if CC LV2-C Closed Center Kit Brand Hydraulics | Valve Parts & Accessories | Hydraulic Valves | Hydraulics | www.surpluscenter.com

IF it looks like that....let us know