hi colleagues,

i have Komatsu FD50-7 diesel forklift. it has a problem. this problem is the steering orbitrol is heavy to turn. when I am throttling, orbitrol being light. the hydraulic pump is new and original control valve is new and I checked all of the hydraulic system I couldn't find any problem. I guess the hydraulic pump has low pressure for orbitrol.

Are There any colleagues had been saw this problem?
I think I have to increase oil pressure. how can I increase the oil pressure ?