2001 vitara, brake pedal goes to the floor, so replaced rear brake shoes, wheel cylinders springs, and new drums, blead all the brake lines all new fluid,  still pedal very mushy and will go to floor, next step new master cylinder, anyone else had this or a similar problem,  now I'm just changing parts hoping I hit the right one, thanks.

If the pedal is going to the floor and there is no fluid loss caused by an external leak, the problem is more than likely an leak internal to the master cylinder.

A friend had an issue with his break booster having a leak, it produced similar behavior to what you are seeing.

A leaking brake booster will not cause the pedal to drop to the floor - all the booster does is reduce the pedal pressure required to create a given amount of hydraulic line pressure - a failed/failing/leaking booster will cause the pedal to be higher & harder - try depressing the pedal with the engine off and see what happens.

Here's a quick & easy way to test the booster...

With the engine off, depress the brake pedal half a dozen times, with each press the travel should be reduced, and after the third or fourth time, the pedal should be stopping at about the same point - now hold the pedal down firmly and start the engine - as soon as the engine starts and develops vacuum in the intake manifold, the pedal should drop an inch or so, and then hold steady.

There is no fluid in the booster, only engine vacuum and air, if it's leaking, it's air leaking into the vacuum chamber, and that makes the booster less effective or completely ineffective, which is what you would have experienced when the above test was performed with the engine off and there was no vacuum.

The pedal sinking to the floor is a fluid leak, either external, which will cause a fluid loss or internal to the master cylinder, in which case, there will be no fluid loss

Fordem tried what you said , works just like that, , can't find any leaks and the brake fluid doesn't go down, let my son drive it and his wife, they both said it stops find, soft pedal, maybe it's just me, my truck is a one ton diesel with disc brakes on all 4 corners with a hard pedal, she stops quick , maybe I'm just not use to drum brakes on the back. Sure feel mushy to me.

Mushy and pedal sinking to the floor are different things to me - if they think it stops fine, then the pedal cannot be going to the floor.  Does the vehicle have ABS brakes?  If it doesn't, it will have an LSPV near the rear axle that needs to be included in the bleed process.  In my experience disk front/drum rear has little or no difference in the pedal feel or stopping power when compared to four wheel disks, and if it makes any difference, I grew up around four wheel drum.

It has abs, the pedal does not go all the way to the floor now, but it sure feels close, waiting for a neighbour to get back from his summer camp, he has a samurai and a sidekick has worked on Susooks for a long time , going to get him to check my brakes.