Hydraulic question on older 530

[nothingbutdarts]

I'm having issues with under power situation and tilt hydraulics that kill the engine even when lightly touching the pedal. This weekend I took off the hoses going to the tilt function and put a hyd. pressure/flow check insturment on it. Pressure seems to peg around 1,500 psi. though it stalls out the engine when it reaches this psi. Mind you I live at 8,700' so the engine is underpowered because of altitude. My question is this: lightly depressing the tilt pedal it pressurizes the one hose and goes to full psi (1,500) and has no flow, when you push the pedal a slight bit more than the control valve must open the return pressure hose port and the psi drops to around 500psi and has about 9 gph flow. I do not understand why, when lightly pressing the pedal it pegs the psi with no flow. Has anyone ever experienced this?

 

[nothingbutdarts]

Could not figure how to edit my first post so, the flow figure was 9 GPM not GPH.

 

[Tazza]

Could not figure how to edit my first post so, the flow figure was 9 GPM not GPH.

That is strange.... I wonder if it could be a load check casuing this or damaged spool?

 

[nothingbutdarts]

That is strange.... I wonder if it could be a load check casuing this or damaged spool?

Where would the load check valve be located? With in the valve body?

 

[Tazza]

Where would the load check valve be located? With in the valve body?

Yes, in the valve body, behind caps. Look for head headed caps, they should be below these. Not sure if it's the issue or not, but something to look at all the same.