ridding lines of old fluid

[19674x4]

ok, i plan to change my master cylinder tonight, my question is how do i get the old fluid out of the line before i put the new stuff in. do i just bleed it out, or compressed air, or just bleed out the master cylinder while it is still attached? also, should i do anything to the lines before i put new fluid in them.

another thing, when i take the master cylinder out of the fire wall, do i need to replace anything?

is one bottle of brake fuild enough?

[qman]

One large bottle should be enough and all you have to do is bench bleed the new master and put it on. Then bleed each line until you get new fluid coming out. Start with the wheel that's the farthest away and work your way to the closest. Pass side rear, driver rear, pass front, driver front. I have a little bleeder tool that helps real well. It is a small piece of clear plastic tubing with a check valve and black rubber attachment on one end. You put that onto the bleeder valve, loosen the valve, and run the other end into an old bottle or jar to catch the old fluid (I keep an empty fluid bottle for just this purpose.) Then you can bleed the brakes yourself. The check valve will only allow fluid out and keep air from entering. The clear tubing will allow you to see when the new fluid has made it. Once you get the furthest wheel bled then it only takes a couple of pumps each to bleed the others. I bought the bleeder tool from Checker auto 5-10 years ago.

[QC]

DO NOT skip the bench bleeding part! You'll be pumping a long time to get all the air out if you do.

[flyboy2610]

OOOOOOOOOHHHHHHHHHHHH!!!!!!!!!!!!! Gadgets! I LOVE gadgets!
You can get colored brake fluid. Just use that for your new fluid and bleed the brakes until the colored stuff comes out.

[19674x4]

alrighy, thanks. didn't get to it tonight but this weekend, will do.