[skyline8409]

I didn't read every post but the reason behind opening the bleeder when pushing the pads back is to get the old fluid out of the system. You are not going to get air in the system. That is silly talk.

It is annoying on bigger caliper cars opening the bleedersss and pushing the fluid out at the caliper. After each caliper check the reservoir. I let mine run low once and regretted it. Just made more work for myself having to then make some lines up to bleed the master.

 

[skyline8409]

You are not going to get all the old fluid out of the system just by moving the calipers. You might get air in the system.

If you are going to open the bleeders, then just flush (drain and replace) all the fluid and bleed . . .

I have never seen air get in the system from opening the bleeder on a caliper that was already air free.

There is a secondary reason as well. Pushing the pistons in against the pressure in the lines is much harder. On cars with sliding calipers you don't even need the screwdriver method to move the caliper. You just crack the bleeder with a hose and lean back on the caliper with your body weight.

Like you said though you are never going to get every drop of old fluid out but life is easier when you crack the caliper bleeders.