The original builder skimped on the hydraulics. With the different dividers and splitters and a missing valve....One hose should go from the pump to the geared splitter and then the line/volume going to the loader valve should be split. Then 25% of the flow should got to the loader valve and 25% would go to the auxiliary port . The second line coming from the geared divider should be split so that 25% goes to steering and 25% goes to the travel valve for forward and reverse. I think the one splitter/divider is messed up. The other splitter/divider is not there so the valve for the bucket gets 50% of the flow. The travel & steering valve gets 50% of the flow as well because there is nothing to split the flow there either. All new splitter/dividers and the addition of the now missing fwd/reverse valve would probably fix it right up.
I missed the link when I replied yesterday. Definitely a loader valve. Not recommended for a drive control valve.
How about you at least make a drawing of how your machine is plumbed. we can off all kinds of advice that's totally worthless because it doesn't apply to your issue. rotary splitters don't compensate for OH shits down the road they are in fact fixed output based on input. BIG basic for IMO. That's hydraulic term for I Move Oil. rotary gear hydraulic component are ALL IMO if one output changes it affects EVERYTHING. IMO components will go until something blows up or the drive input just cant hack it.
Pressure compensated splitters however will adjust to keep things equal. If your missing one where there is supposed to be one..... HELLO.. problem.
400 PSI inlet pressure to the first device after the pump is an issue. you need to figure out the cause for that before you can even start any thing else. most likely when you find the restriction that's causing the back pressure you'll find the Base cause of your issue. Fluid power is amazing and wonderful. it can be used for a multitude of purposes BUT fluids don't compress so if some thing isn't right some thing is going to break.
OK I'm Done preaching I won't say any more without seeing what we are supposed to be figuring out.
