Brake pedal goes to the floor , replaced master cyclinder , replaced front pads , adjusted rear brakes , bleeded all the lines , still the same .

for the pedal to go to the floor there is still air in the brake system. Start again starting from the longest line bleeding each in turn to the shortest line . make sure you have adjusted up the rear brakes before bleeding as every time you press on the pedal the shoes expand right out and when you take your foot off the pedal the shoes go all the way back in. adjust them manually and do not rely on the self adjuster as it only adjusts on wheel movement

You've done major work and now you'll need to completely bleed air out of the system, to get the fluid to go all the way through. You may also need to adjust the rear brake shoes.

First, bleed the Master cylinder to get fluid through it. This should have been done before installation. Loosen the lines at the M. Cylinder and fill up the reservior with brake fluid. Pump the brake pedal slowly with the cover on the M. Cylinder to prevent fluid from splashing out. Once you've got fluid coming through the M.Cylinder, tighten the brake lines at the M. Cylinder.

Bleeding the brakes is a 2 person operation. You always bleed the brake the farthest from the master cylinder, then the next, the next, and finally the drivers front brake which is the closest to the M. Cylinder.

If you are unfamiliar with this process, you need to remember that you can't let the brake fluid get low in the M. Cylinder, or you have to start all over when air gets back into the lines.

When one person pumps the brakes, after several pumps hold the pedal down as far as it will go and keep pressing to the floor as the other person loosens the bleeder valve. Don't let off of the pedal before tightening the bleeder valve. Then repeat until all of the air is gone.
Teamwork and communication. Both of my wives were able to assist me in bleeding brakes.

You will have to add fluid and repeat this process until you have a firm pedal.

One man bleeder valves work if used properly, but who tells you what is happening at the other end while you're pressing the pedal?

Good luck.

Sounds like it still has some air in the system or a bad master cylinder. First try bleeding all air, there is definitely some air left in the lines and this is most probably causing the problem. Bled the lines at the bleeder screws on the calipers. ---------- There is air left in the brake line.Any time the brake system is opened to replace brake lines, caliper, pads etc etc.Mostly the air enters the system, and that air has to be completely bleed.Otherwise the same symptoms , what you are getting will be noticed.-------- Brakes can be bled manually, with a power bleeder, injector tool or vacuum bleeder.IIt does not make any difference which method you use as long as all the lines and components are flushed with enough fluid to remove any trapped air bubbles or air pockets.----
The most common bleeding procedure is to bleed the brake furthest from the master cylinder first, then bleed the other brake that shares the same hydraulic circuit (which may be the other rear brake on a rear-wheel drive car or truck, or the opposite front brake on a front-wheel drive car or minivan). After these have been bled, you then bleed the other brake circuit starting with the furthest brake from the master cylinder.--------- When the complete air is bleed from the line, the brake should be firm when car is on.In your case brake brake pedal is loose and goes almost to the floor when car is ON.This is due to Air in the line.Get the complete air bleed from brake line.------- This will help.Thanks.Helpmech

yes may need to bleed lines at master cylnder

try bleeding them more,start with the right rear,then left rear,then right front ,then left front, always bleed the brake that is furthest from the master cylinder, sometimes you have to bleed them several times until you get a steady stream of brake fluid.

Start with brake in the rear that is the farthest away from the master cylinder ( if your master cylinder is on drivers side start with passenger rear,pump up brake pedal until hard have someone else open bleeder valve until air or fluid squirts out,while holding brake pressure even if goes to the floor dont release pedal until bleeder valve is tightened or you will **** air back into the line,do this several times making sure you get a full stream of brake fluid and no air,continue to other rear wheel and then proceed to front wheel furthest from master cylinderand then final wheel. if you still don't have brakes change master cylinder and bleed all brakes again.

ok there are a few things you need to check.. you said you changed the master cylinder.. did you bleed the braking system after???

• remove from wheel,,
• locate bleed valve on caliper / or unscrew one of the lines
• pump brake and push right down and hole,,
  
• repeat plugging the lines with your finger ,,
• repeat the above 2 steps a few times
• tighten the bleed screw while holding the brake right down..

if that fails ...

if that fails try adjusting the brake up.. its on the rear tires,, remove one and them remove the shield protecting the brake shoe,, see the turn bolt that adjust the pistons,, adjust that a bit until the brake is in the desired position..

check your disc pads to see if its wron out..

check your booster / change it..

got air in the lines, need to bleed it out. if not you might need a new master cylinder. but since you just had brakes worked on it's most likely air

do you have a self bleeder kit? first off, you have to bleed the master cyl back into its self and the combination valve before you go to the wheels. when you do that, I think you will find that you have air in the lines. disconnect both brake lines from the master cyl and put the bleeder kit fittings on the master cyl, then put the rubber tubing with the kit on the fittings and submerge it in the brake reservoir. make sure its full. then pump the pedal until you get a hard pedal. if that is the case, reconnect the lines to the master, then have an assistant pump up the brake pedal with the engine off, and bleed the combination valve which should be connected to the master by steel tubing. pump it up, then hold it down, and crack the fittings loose, one at a time until the pedal goes about half way down, but do not release the brake pedal until the line is tight again, otherwise you will **** air in the lines. after you do all that, go to the farthest caliper or wheel cylynder from the master and bleed that with the same technique,and dont release the pedal until you close the bleeder screw. unless you have a major prob, this will work.

are your rear drums set up? why did you bleed the brakes. when only when you installed new pads?