Freightliner century 2000. Hard steering

Sometimes the steering gets a bit stiff and sometimes not . I have changed the steering box twice . The power steering fluid seem fine . I am thinking the problem is from under the steering wheel itself . When it stops being stiff , I hear a small pop under the brake pedal area . Sometimes ,when I slam the brake pedal, the stiffness goes away . I sprayed pb blaster under that whole area and it seem to get better , but the problem is still there Maybe it has something to do with the steering adjusting valve ? Not tottye point of the truck not runningr and trying to steer but a bit stiffness. Any suggestions?

 

Since i have had the truck I have never done it . This will cause the steering release/engage tension when the brakes are stabbed ? These 2 mechanics couldn't figure it out and replaced the steering gear twice . I am telling you , when I spray under the column it gets better for a minute

 

Which joint more likely ? The joint on the rod and the steering gear or the one inside the cab and on the bottom? Is there not another joint that's covered up and meets the fire wall ?

 

Fixed it myself . The problem was the steering shift . The old one was stuck going up and down . Had to look on YouTube to take the old one out . Lined up the marks and I was good to go . Easy fix