Relief valve shims

[AndyG]

I checked the system pressure on my TC40D and found it to be a little low (2200 psi). Thanks to past threads I have found the spring and it only has one very thin shim under it. I need to get some more shims so that I can adjust the pressure to 2500 psi. I have a Case dealership handy but they play dumb when I ask for NH parts. What are the NH and Case part numbers for the shims that I need?

 

[RickB]

I checked the system pressure on my TC40D and found it to be a little low (2200 psi). Thanks to past threads I have found the spring and it only has one very thin shim under it. I need to get some more shims so that I can adjust the pressure to 2500 psi. I have a Case dealership handy but they play dumb when I ask for NH parts. What are the NH and Case part numbers for the shims that I need?

Ask for shims for a DX 40. They don't have to know what you own or are working on.

 

[jinman]

The shim kit for a New Holland is SBA340293230 according to my Repair Manual; however, NH is notorious for changing part numbers. If you want to order online, I'd recommend Neil Messick. Go to messicks.com and look up their telephone number. If the part doesn't pop up online, you can get them to cross-reference it over the phone and have the kit come to you in the mail.

The kit will have 6 shims. Three are 0.3 mm and three are 0.1 mm. The 0.3s change the pressure about 150 psi and the 0.1s change it around 50 psi according to my Repair Manual. I have never needed to do this to my tractor, so I don't know for sure.

EDIT: I just went to messicks.com and entered that part number. It is the correct number and they can get one to you for $8.59 plus shipping. It's the same number for the Case or New Holland part, so your Case dealer would have the same number. Neil Messick does not have one in stock and your Case dealer may also not have one.

 

[AndyG]

Thanks for the part #. The Case dealer likely doesn't have it in stock but I pass within a 1/4 mi of them on the way home so it would be silly not to ask.

 

[JC-jetro]

Jim provided good pertinent info. If I needed it now ,I would buy a few flat Stainless steel washers, mic or look up the thickness and put them in there. That should suffice to get you in the ball park. The shims that I have seen on mine were no different from a flat washer with the exception of a hole in the middle.

JC,

 

[AndyG]

Jim, I've already been through my washer inventory and didn't find what I need. I thought that I should see how hard it is to get the "right" tool for the job.

Thanks

 

[JC-jetro]

Jim, I've already been through my washer inventory and didn't find what I need. I thought that I should see how hard it is to get the "right" tool for the job.

Thanks

Andy,

You don't normally have a single solitary Shim/washer. usually several of them are sandwiched together to increase the stiffness of the relief spring. if You end up with 4 washers/shims totaling lets say 3 millimeters then a washer 3 millimeters thick would have exactly same effect. We're adding thicknesses to total out what is needed to give required pressure.

JC,

 

[johnnylight]

Andy,

I would try changing the hydraulic filter first before going for the shim kit.

 

[texasjohn]

My Kubota was some low on pressure following a dealer's test (at the time I didn't have a pressure gauge). Dealer mechanic installed what he admitted was simply a washer and retested the pressure... yep, higher and just a gnats eye brow over spec.....

My lesson learned.... a shim is simply a washer, properly sized and of hard non rusting material.

 

[jinman]

Andy,

I would try changing the hydraulic filter first before going for the shim kit.

Johnny, Andy's tractor has a hydrostatic transmission. All the fluid for the transmission and the main hydraulic pump is pulled through the same hydraulic filter. If the hydraulic filter was restricted enough to cause a hydraulic system pressure problem, Andy would also be experiencing erratic transmission problems. Since he is not reporting any problems that sound like a cavitating pump, I think his filter is fine. I have never had any problems with my filter even when I went slightly over the recommended hours before changing fluids.

You suggestion of checking the filter is a good one, but I just don't think the symptoms point to it in this case.