Fitting new brakes

[antgel]

Just reading through Haynes before fitting new rear calipers, discs and pads.  Mk 2 Golf GTi.

They suggest that the replacement caliper is topped up and bled off the car.  Is this important?  What's the point?

Is it fairly easy to change the bearings at the same time?  I wouldn't have bothered, but looking at the procedure, it seems that if I'm replacing the discs, I might as well.  If I do, do I *have* to use a new split pin?

[rubjonny]

I think the reason is on some calipers the bleed nipple is at the bottom, so you need to take em off and turn em upside down to get all the air out