brakes

When replacing calipers, pre fill them with brake fluid and put the little cap back on to keep the fluid in. Leaves a lot less air in the system to bleed out.

In reply to zordak :

I worked for years in a shop by myself or close to it.  Manual bleeding was rarely an option.

I always gravity bled, which gets all of the air out except for that which is in the hose.  Pumping the brakes up to push the pistons out would push the air into the calipers.  Gravity bleed until the air bubbles stop coming up and you're done.

And if it has an integrated parking brake, work the cable or smack the caliper with a hammer, gets the trapped air in the mechanism to pop free.  This goes for any bleeding method.

Leave the bleed valve open when assembling, and work from the inside out (hose to hard line, then hose to caliper, repeat as necessary for weird Vanagon stuff). It'll gravity bleed as it goes, including the hose.

In reply to Keith Tanner :

I speak of slapping new calipers on an already existing and bled system

For an all new system, once I realized that I have a reverse bleeder, I am sold on that concept and won't go back.  It pushes fluid in from the calipers UP.  Empty master cylinder?  You can bench bleed until you are blue in the face, making a big mess all over the workbench and floor and probably your pants and shoes, and then put it in the car and get fluid all over the inner fender and still fight air bubbles in the master, or you can pump fluid in from the caliper end and pump all of the air up through the master and out of its compensation port into the reservoir.

So do it! Fresh caliper, install with the bleeder open.

I don't like pressure bleeding, I've never been able to get as good a pedal. Gravity is my favorite. Is just slow. 

I'm a gravity bleeder, and I never push fluid upstream on a car with ABS/VSC

My experience with gravity bleeding is it does not work if there is a loop in the system. An air bubble stays at the top of the loop.

Got this tip from a large truck garage. Hydro boost systems and getting power steering pump bled. If after trying all the other things to bleed the air out of the system do not work, try this. Find or make a lid for the reservoir with a fitting to your favorite vacuum pump and put the system under vacuum. leave it set until you see the level drop. This may take a while.

zordak said:

Got this tip from a large truck garage. Hydro boost systems and getting power steering pump bled. If after trying all the other things to bleed the air out of the system do not work, try this. Find or make a lid for the reservoir with a fitting to your favorite vacuum pump and put the system under vacuum. leave it set until you see the level drop. This may take a while.

I've done this with brakes as well. For a Tilton MC, I just bought a spare MC top, installed a Schrader valve into it and attached it to my vacuum pump. I've used it for brakes, clutch, and even an old school Tudor-style pump windshield washer setup.