Hitachi ZX140W-3 Hydraulic pump Noise

[HitachiEX]

Hello, I received helpful advice here the last time I had a problem so I am back again. I have a Hitachi Zx140W-3 (HPV 118 Hydraulic pump ) the pump is Producing 340 bar of pressure at hydraulic pump 1 and only 260 bar of pressure at Hydraulic pump 2, this is accompanied by a cavitation whine, I plan to remove the hydraulic pump from the machine shortly to inspect . Does anybody have any other suggestions or test I should carry out before removing the pump?
Any help greatly appreciated.

 

[Diesel Dave]

What are the pump1 and pump2 control pressures ?

 

[HitachiEX]

What are the pump1 and pump2 control pressures ?

I don’t know the exact figures. I do know that there was a difference in them when I Checked on the monitor . I’ll check out the exact figures on Monday.

 

[HitachiEX]

What are the pump1 and pump2 control pressures ?

Pump 1 Delivery pressure : 33.5 MPa
Pump 1 control pressure : 1.90 MPa

Pump 2 Delivery pressure 24.4 MPa
Pump 2 Control pressure 2.50 MPa

These readings were taken when holding back the the boom up fully.