hydraulic schematic

[kpk]

Hi,
I have a TC25D with a 7308 fel and backhoe using the NH hydraulic kit in which you switch the hoses and disable the 3pt arms when connecting to the bh. My question is this. What governs the pressure to the bh valve block? Is it the relieve valve on the fel or some internal relief inside the tractor? It would be really nice if we here at TBN could get a hold of New Hollands hydraulic schematic for our tractors. Any factory guys listening???

At any rate, maybe someone out there knows the answer to my question.

One more thing, what happens to the oil in the fel valve when the fel relief trips? Does it go through the power beyond port back to the manifold on the side of the engine or is there another line (one of the steel ones) that the valve dumps the oil to to return to sump?

 

[tawilson]

I like my New Holland tractor, but one of my gripes is the lack of available online material. I wanted a owners and parts manual for my loader, $20 each for a cheesy manuals that someone printed out on an inkjet and stapled together. Many companies make this material free for the downloading.

 

[RickB]

There is a main system relief valve located in the distribution block just downstream from the hydraulic pump. The loader control valve also has its own relief valve which is set a little lower than the main relief. Oil passing through the power beyond port of the loader control valve and on to either the hitch/remote valves or the backhoe control valve will be regulated by both reliefs previously mentioned. oil passing over the FEL relief valve flows directly back to the transmission housing via the return tube which also carries return oil from the FEL valve work ports. The backhoe valve may also have its own main relief valve and certainly has multiple circuit relief valves that protect dedicated circuits.

 

[jcollins]

I am certainly no mechanic (give me a set of tools and it will never work again!) but found this that might help along with what Rick gave you.

 

[jcollins]

Send me a PM with your email and I will email the file .pdf that I was trying to post. Talked about the power port on the front right side of the tractor. I think that would help. Web site said it over allowed limit.