Another Stinking Hydraulic Lift Question

[carterd 20]

I am assembling a bastard 917H from a mixture of 916H back half, and the 917H front half. I scored the complete front with everything I needed for hydraulic lift, except the rear trans and pump. No big deal, because I've done my homework from simpletractors.com and I know that I need to do some spring swapping and possible shimming. So I borrowed the rear half of my 916H and away I went!

After doing the spring and shim thing, I cannot get any pressure above 150psi! while it is possible that my gauge is faulty (I borrowed it from an older gentlemen who isn't so gentle), I think that at some point it should lift my mower deck. Nope, Nothing with the side relief body installed. 

When I removed the side relief body and reinstalled the plug, it lifts my mower deck. Not with a ton of conviction, but enough to make me able to use it this summer mowing. 

What am I missing? this tractor sat outside for a long time, so maybe the valve body needs to be rebuilt?  I would really like the hydraulic lift to be working by winter, due to nerve damage in my left arm, it makes lifting a plow really difficult. 

 

Dallas