Re: Hydraulic Fan
The hydraulic fan normally idles at around 500 rpm as soon as the engine runs, but will speed up depending on some inputs to the PCM. Coolant temperature is one input, but also AC pressure.
Didnīt you remove the coolant temp sensor connector during the power steering pump replacement and maybe forgot to re-install it? When there is no coolant temp signal to the PCM, it will failsafe put the hydraulic cooling fan into high speed mode.
Also too low coolant level can do this.