My 1960 something Ford 4000 backhoe will not keep the hoe up and I was wondering if it's the six spool valve body. If you pull the lift lever up, it lifts slowly and not as powerfully as the other controls, all other controls are fine. It does not have very good downforce either. The machine does have a valve that leaks but that valve is by itself and switches between the loader and the backhoe
Could be a problem with your valve body, but might be your boom cylinder piston bypassing within the cylinder bore.
How fast does it go down? it might be normal, this is an early backhoe and might not have terribly tight valve tolerances, or load checks in the valves, and I would expect the boom to be slow and relatively weak compared to the feel of the other functions. One quick way to check, is hold the boom down for ten seconds with the boom against the ground, then shut the engine off. Do this with everything cold, and it should warm something up where it's leaking. The hydraulic pump might be slightly warm, the relief valve should be warm. The cylinder should have no warmth around where the piston is. If you can't find anything warm, go another ten second.
The machine does not do this as bad when the oil is cool and if you're lifting the hoe and you pull another lever. The whole boom drops down and if you lift the boom all the way up to stow it away, it falls down like a foot when you let go of the lever and if you have the stick all the way out and the boom down the and you curl the stick in it will push the boom up
Please proof read this to be sure the sentences are what you intended to say. Or re write it with separate paragraphs for each instance. I'm just way too confused with all the thoughts going on in these two sentences to makes sense of what's going on.