Before replacing a power steering oil pump for a whine noise condition, check the oil pump reservoir filter screen for contamination. If the filter screen at the bottom of the oil pump reservoir is clogged, it may cause the pump to aerate and cause a whine noise.
If the filter screen is clogged, replace the reservoir and reconfirm the condition. See Fig. 1 below.
Note: For proper inspection of the screen, it may be necessary to empty the power steering oil pump reservoir.