M5400 hydraulic fluid in engine

[motmow]

I have an M5400 that had weak hydraulics. Both the 3 point and the loader are weak but power steering is good. The hydraulic fluid had water in it so I changed the fluid and filters with no change. I took out the safety valve and cleaned it with no change. I took the hydraulic pump apart and resealed it and engine started filling with hydraulic fluid. I changed the pump head seal and started the tractor and again the engine filled with hydraulic fluid. Could the safety valve fail and cause overpressure and blow the pump seal?

 

[greenacresnorth]

are you replacing pump seal with the right one and installing in the right direction? do you have the pump running plates turned the right direction? what does shaft look like, its normal for there to be a running mark on shaft but any ridge you can feel with your finger nail is to much. any time I have seen a gear pump or motor pump oil out the shaft seal its either sale is installed backwards or wear plates are put in backwards.

 

[Tx Jim]

If you disassembled hyd relief valve did you then check system pressure with a gauge??????