B1750 dt. Hydraulic Control Block Pressure Relief

[Titan17]

It has been a long while since last post. Previously I posted repair questions regarding my B1750 hyd. pump replacement. Dan (old hokey) was an immense help!!! He set me straight on everything from where to buy pump to setup and relief valve settings.
I sold the tractor 2 years ago to a friend with no problems to speak of. Recently repacked lift / curl cylinders and did a pressure test at work port. It was running low - 1400@2000 rpm. Increased loader relief valve to 1600 as high as it would go.
Checked pressure at block - also 1600psi.
Pulled relief valve from block and would like guidance shimming/adjusting pres. relief before I attempt to do the job. (I returned the loader valve relief to original pressure until main pressure is at normal psi.
New pump was previously installed, screen is clean, fluid flushed.
Pictures are attached.
Hopefully Dan or Wolf man will respond but any first hand experience will be appreciated. T. Y.

 

[North Idaho Wolfman]

It has been a long while since last post. Previously I posted repair questions regarding my B1750 hyd. pump replacement. Dan (old hokey) was an immense help!!! He set me straight on everything from where to buy pump to setup and relief valve settings.
I sold the tractor 2 years ago to a friend with no problems to speak of. Recently repacked lift / curl cylinders and did a pressure test at work port. It was running low - 1400@2000 rpm. Increased loader relief valve to 1600 as high as it would go.
Checked pressure at block - also 1600psi.
Pulled relief valve from block and would like guidance shimming/adjusting pres. relief before I attempt to do the job. (I returned the loader valve relief to original pressure until main pressure is at normal psi.
New pump was previously installed, screen is clean, fluid flushed.
Pictures are attached.
Hopefully Dan or Wolf man will respond but any first hand experience will be appreciated. T. Y.

WHOA... Put that part back in, that's NOT the pressure relief valve , that is the divider / proportional valve, do not change anything with it.
The pressure relief valve is under the tank / overflow fitting (#150).
The pressure adjustment shims are #190 in the picture.

 

[Titan17]

Thank you. This is why I ask questions here. It sure looks like a pressure relief.
Guess this splits flow to power steering at lower pressure/flow.???
I will now bring pump pressure up at the "P" line before loader valve. I will keep it under 2000#. Then adjust at the loader control pressure relief. That's a screw adjustment or should I shim it. I have plenty of various thickness shims.

 

[Titan17]

Is there a formula for shim thickness to raise pressure 300# or trial and error.
I bought an assortment of shims while back. .001 up to .010. I could stack them and check pressure till I reach 1900#. New owner doesn't need or want any higher than that. He's actually satisfied with 4-500 lbs lift at bucket. There's a permanent mounted PTO driven backhoe on tractor so 3ph will never be used.

 

[North Idaho Wolfman]

Is there a formula for shim thickness to raise pressure 300# or trial and error.
I bought an assortment of shims while back. .001 up to .010. I could stack them and check pressure till I reach 1900#. New owner doesn't need or want any higher than that. He's actually satisfied with 4-500 lbs lift at bucket. There's a permanent mounted PTO driven backhoe on tractor so 3ph will never be used.

The pressure is all dependent on the spring tension and that varies, I didn't read any set sizes in relation to pressure, start small and work up.