Steering pump bleeding

I am about to fit a replacement steering pump to my 2000 model Jimny.  Does the system need bleeding afterwards - and, if so, how?
Many thanks in advance.

Further to my query about bleeding the power steering, I have now removed the belt thinking the pump is worn out as the steering makes a whine all the time that increases to a nasty growly whine the further the steering wheel is turned. However, I find the pump feels fine and smooth when turned by hand, except for 1mm end float on the pulley, but the idler has some slop in it although spins quietly when not under tension.

My secondhand replacement pump feels exactly the same.

No oil leaks.

So, do I go to the trouble of fitting the s/h pump only to find that the noise is still there?

Or do I just replace the idler bearing in case that is the problem?

Or . . . could it be something else entirely?  Do the steering boxes whine like this?

Thanks for your advice guys, I'll get this sorted one way or another!

Pumps can whine if they are low on oil or if the strainer in the reservoir is blocked (not all cars have a strainer).
Bearings can also make odd noises. If you have any movement in the idler bearing I'd recommend replacing it. It's up to you if you just do the bearing first or both the bearing and the pump.

As far as bleeding is concerned, fill the reservoir then start the engine and keep winding the steering side to side, topping up as needed. In the beginning it may well make all sorts of whines and gurgles as the oil sorts itself out.

It's much more likely to be the idler bearing than the pump.