BRAKE PEDAL GOES ALMOST TO THE FLOOR, DASH LIGHT ON FOR BRAKES, PEDAL APPEARS SPONGEY.

run a fault code reader to reset the abs and trac lights as the trac light uses the same sensor as the abs.. IF the pedal is still soft then there is still air in the brake system. You may have to crack the lines at the master cylinder first and bleed there first then start at the longest line and work back to the shortest

You need to add BRAKE fluid. After that, blead your brakes. You need to find out where the brake fluid went. If there are no leaks, you need to check the remaining life on all four brake sets. If you have no leaks, chances are pretty good that you need new brakes.

This sounds like a bad brake line, these trucks are famous for rotted lines behind gas tank, make sure there are no leaks, this sounds like a leak or a defective master cylinder, if this is the same problem then i would say it is a line also check the rear brakes for leaking wheel cylinders unless you have rear disc brakes, check calipers for leaks.

Take a good look at brake system for leaks, hold brake pedal a few times and let is sink to floor , do it about ten times and then look for a leak, good day

if a master cylinder is bad and you are sure you have all the air out and no leaks.pedal will go to floor , running or not. if booster is bad it will cause a hard pedal. but if master cylinder is bad it will turn on a brake light on dash if it works. make sure the wheel cylinders are not leaking. I beleive that the master cylinder is bad, or you have a leak somewhere. If the master cylinder is functioning properly, the brake pedal will depress to a certain depth and no further.

The brake system has sprung a fluid leak, don't try to drive it until it's repaired. You may be able to locate the leak by looking under the car for fluid on the ground. This could be anything from a rusted-out steel line to a piston on a wheel.

that is definitly a brake booster problem the air your hearing is bypassing the pressure valve located in the booster that could also make your pedal spongey

It sounds like you have quite a bit of air in your brake lines. You may need to have them bled out to relieve the spongeyness. If the brake fluid resivoir is staying full then this would be the most likely cause. Hope this helps.

Thry to pump and drain every single breaking calier, maybe there is pocker of air in the break lines.

You need to crawl under the truck and inspect each brake line for leaks. You also need to check wheel cylinders and calipers. The chances are pretty good that you will find a small leak in a line or a wheel cylinder leaking, pay close attention to the rear of the truck because that is normally where these problems occur. Hope this helps.

still have air in the brakes