I replaced rotors calipers and rear brakes old drums though. Bled the system numerous times and when I start the truck the pedal goes to the floor any ideas

 

Welcome to the forum

What YEAR Ranger?
Also engine size, but that shouldn't matter, just good to include with questions
Rear ABS or 4 wheel ABS?

Did you do the brakes on all 4 wheels just because it was time?
OR
Was there an issue prior to doing the brakes?

The front and rear brakes use isolated systems, but they share the master cylinder

How did you bleed the system?
Power bleeder or had a helper press down the pedal?

You can open the bleeder at any wheel and fluid should slowly come out, called gravity bleed, it flows because Master is higher up than the wheels and there should be no closed valves if brake pedal is up

 

Also, to note - If you have an ABS equipped truck, and the master ran dry for any reason, there is likely air in the ABS module. You can remedy that by using a scan tool while bleeding. Or, the "redneck" way is to go down an isolated dirt road, and slam on the brakes. You want the ABS to activate. This should help push the air bubbles out of the module and down into the lines, where they can then be bled out.