Power Steering

1999 GMC Sierra K1500 SLE 4×4

Was hard to turn left unless RPM’s were up, I installed a new power steering pump, still have same problem, any suggestions?

2000 Infiniti QX4 power steering issue

Infiniti QX4 2000 mi:203k Power steering issue. Working fine until I used 4WD. Now regardless of 2WD / Auto / or 4WD steering very hard.