Mercedes Benz repair: Poser Steering Gear Box, power steering fluid, cross member

Question
I replaced the Power Steering Gear Box and after hooking everything back up and putting Power Steering Fluid in the resevoir....the steering is very hard - like no power steering at all.  I assume that the lines need to be bleed (or as some point they will self-bleed?  Any suggestions on if air in the lines is the problem.  I did start and turn the wheel - lock-to-lock several times -but it is still stiff.  The old gear box was leaking - however, you couldn't tell there was a problem.

Thanks in advance.

The car is a 1998 Mercedes S600.

Answer
Note: wrong fluid will wreck the pump.
Support the front end from engine cross member.
Turn the wheel - lock-to-lock thirty times, checking fluid level every five cycles.

Leave it in the air.

Start the engine, turn the wheel - lock-to-lock thirty times, checking fluid level every three cycles.

If this all fails, there are only two possible answers:
#1. The hoses are reversed on gearbox.
#2. The pump has failed.