I just purchased a second hand 2000 Hyundai Elantra, everything works and looks fine, except one.

The steering is very stiff. The power steering fluid looks good, and the power steering pump seems to work.

The car supposed to have "steering assist" which gives the wheel a light touch at low speed, for easy parallel parking. But it does not seem to be the case, I need to use both hands to turn the wheel at low speeds.

I found a WEB post that states the following...could this be the case? Steering rack must be replaced?
"On a power Hyundai steering rack, hydraulic leaks often cause the power assist to become spotty or unreliable".

I would rather see the dealer as a last resort, to pay an arm and a leg for expansive diagnostics.

never ever heard of steering problems with any Hyundai, must be your steering rack or the pump. Even is the pump is hooked up and turn means its working.

I also have a 2000 Elantra and with 185k km (about 115k miles?) and the powersteering is still strong.