I recently and stupidly tried to drift my 99 ls400 around a corner. After exiting the corner my power steering felt stiff and it made a grinding noise. I figured the power steering pump went out from the excess force on it so I replaced it thinking it would fix my issue. I got it replace and bled the system with the front end off the ground. While it was in the air it had no issues turning smoothly without any clicking our grinding, but as soon as I put it in the ground it went right back to grinding and having very heavy steering. My car does have the power steering valve delete so that might be part of the issue since it's especially heavy at low rpm. I'm gonna replace the pump again with a different brand and install a new valve and hose lines and hopefully it will fix it. I really don't want to have to replace the rack and pinion because it's not leaking anything so I don't think it went bad. Please let me know if you have knowledge about this issue. Thanks in advance!

 

drifting it should not have caused any issues (unless you hit something like a curb or another car) but i imagine you were possibly low on fluid and sucked in air while under high lateral-g load sideways (even for a moment) - that's just a theory.

keep bleeding the system, adding fluid and turning the wheel from lock to lock a few times to cycle the fluid through everything, with the engine running. where did you get your replacement pump?

 

See attached for proper PS bleeding procedure.