Hydraulic Help

[leonz]

First off you never adjust a relief valve without a proper hydraulic gauge.

In a gear pump the oil flows around the gears from the inlet/suction side to the outlet side not through them.
After the oil leaves the pump the resistance created by the spool valve or hydraulic motor under load creates pressure in the hydraulic system.

Can you please provide more detail exactly as to what type of spool valve you have there as it is very important.

Your description of the valve is very odd as a spool valve can be open center, closed center, open center with single detent,
open with dual detent or a pilot operated open center spool valve. There are others but for now let's concentrate on what you have.

I have never seen a 4 position open center valve on the mining equipment I operated or repaired they have always been spring centered
open center valves or single detent spool valves.

You have 3 sets of quick connects; where are the 6 hoses that attach to them?? you have to have them connected to a function for the valves
to work and not dump oil under pressure back to the return line to the tank.

If your oil tank has a baffle plate the return oil is stopped and held long enough to cool to some extent before the oil is pulled out by the gear pump.

You will not see any agitated oil until you connect the six hoses and operate one or all three of the valves separately.

 

[LD1]

Where are the three return lines from the functions?
That is the first question I have as they should be attached
to one of the three spool valves in the correct position for return flow.

Plumbing looks fine to me

 

[Scott Y]

In the picture the hoses to the loader are not hooked up yet, the valve bank just has the supply and return hoses hooked up, once I got the system to work I dialed in the relief setting then put loader on tractor, then the control hoses were hooked up. Thanks

 

[Scott Y]

I used a quality liquid filled gauge for setting up the relief valve, the valve is a 4 position, open center, spring return spool valve, the hoses to the cylinders do not need to be hooked up until the system is working properly, it was a snafu on my part, there was a rag in the reservoir, plugged the output fitting. Thanks