Volvo 780 powe rsteering problem any advise?

When sitting still, moving, or both? Have you had the kingpins replaced? If not done correctly, they may be too tight and cause a significant bind. Greased regularly? I'm not sure about that model, but some trucks have a filter in the power steering fluid reservoir that's easy to forget about, that can sometimes cause problems. Best of luck.

 

first of all change PS filter. It is inside reservour.

if u let PS pump work with clogged filter -PS pump may fail and hard steering at low rpm

 

have you checked the u joints in the steering shaft? if one seizes up it will make it hard to turn, if only one side of the joint freezes it will a hard spot then get free then get hard. like it may be fine going down road but when you turn to go off ramp its hard to turn. most people overlook these joints

 

Pablo, how do you change the filter? Is it easy to do yourself?

 

Check both u-joints in the steering shaft.

 

Filter is inside reservour, just pull it out