Fitting new calipers - bleeding?

[bobbler]

Seeing as the weather appears to have cheered up I am going to get my ECS brakes on this week all being well.
One question I have though is the bleeding of the brakes after putting them on. I know I have to do the fronts (obviously), but do I need to do the rears too? I am not sure if air pockets can migrate along the pipes to other areas while the calipers and lines are all off?
If I am thinking to change out the fluid at the same time, would this mean I need to bleed rears as well?

Fine with sticking them all on, but have only done disk and pad changes on a car before. Done a rear caliper on motorbike but that has seperate systems for front and rears.

[grizz]

You don't have to the rear's but it would be a good idea to replace the fluid . Use a hose clamp on the flexi hose to the caliper that you are changing , this will prevent too much fluid being lost and make it harder to bleed the system .

[bobbler]

Cheers Grizz, I was going to do all this today but the missus has nicked off in the car to go swimming GRRRR! Was there when I left on my motorbike to get a couple of new spanners for the job, came home and the car had gone.
Shame, it was a lovely sunny day today here, made use of it and went for a good ride out instead on the bike .

[mikeyquattro]

It's forecast snow at the weekend, so you won't be doing them anytime soon!

[bobbler]

Ah double bugger! Crappy weather for working on the car, crappy weather for riding to work.