Low pressure on Kubota L4740 HST3

[jla414]

I have a newer Kubota L4740 HST 3 that has trouble lifting the 3 point with a heavy bale. I have the knob under the seat set as high as i can get it and run the motor at full throttle.
I can not find where to adjust the pressure. the HST 3 is different from my older HST. Can anyone help on locating the pressure valve and how to adjust it ?
Thank you jla414