Replaced everything in brake system including brake booster,calipers, pads, rotars still won't come to a complete stop It "coasts". To a stop no matter how hard I press on the brake.

If youve replaced all those parts start by checking everything is mounted correctly. If it is even a tiny amount out it will cause issues.
Next Re-Bleed the brake system starting with the caliper furthest away from the master cylinder and do the nearest one Last.

Hello Patricia,

Have you checked the master brake cylinder reservoir for brake fluid loss?

I don't suspect the master cylinder as you have replaced it... but am more suspect of a leaking brake line or fitting which should have
been discovered when you had the system bled.

The only time I ever had a rear brake problem with a 2500 series Chevrolet was due to seized rear brake caliper guide pins...as your calipers are also new that is not your problem.

If your brake pedal feels spongy and travels to the floor board you have air in the system, a brake fluid leak or a failure in the power steering system, such as a broken hose, broken power steering pump drive belt, or failed pump, would result in a loss of pressure to both the hydro-boost and steering.

Find more information here:

. Hydro Boost Power Assist Systems Operation Diagnosis and Repair

I would jack up a front wheel and see if pushing on the pedal with the engine running will stop the wheel from turning.
You need to know if the pressure is reaching the wheels, or if the pads and rotors are too slick to stop the car.
Usually if the pedal is hard, the booster is not working or the brakes are glazed.
Can you stop the car with the parking brake ? That only uses the rear brakes.
You may need a second opinion from a different shop.

I just got a 1999 lincoln myself. And the front brakes locked up on it. Try to take off and it spit and sputter's. And floats around when try to stop. I replaced both brake calipers, pads, and one of the rotars. It had grooves wore in it. And changed the rubber hose going to the caliper. That is what the problem actually was. I noticed that the other side had already been changed beforre. But I wasn't sure. The caliper was rusted up where it got hot from rubbing. And it is posible for them to stick. Autozone $38 ea for calipers rebuilt. 40 for the pads. 20 for the rotar. And 35 for the hose. Now it drives like a dream.

U need the special anti-lock brake (ABS) bleeder adapter to get the air out of the ABS hydraulic control unit, that is why the spongy feel the system is no completely bled of air unless you hook up the tool that holds the hydraulic control valves open for bleeding

Check your Brake Booster. It is located in the Engine compartment. Check the large vacum line attached to that for leaks and make sure it is connected. If it is and you have vacum on the line while the engine is running then your brake Booster is bad and needs replaced. This assumes you have no leaks anywhere else on any wheel caliper and that the brakes and calipers are properly installed. For further troubleshooting and repair steps I recommend the Haynes repair manual on your vehicle.

The rubber brake hose can be clogged or collasped causing this problem Bleed the system of all brake fluid on this and try before replacing the hoses

If you just had the brakes done take it back to that place and if a doityourselfer did it, um i wouuld check each wheel look for missing pad of shoe linning came off or better the hardware the the rear shoes or held down with,Thank you for using FixYa.com, Lee Davidian

First look for obvious leaks under the vehicle, especially the inside area of each wheel... If you see fluid, you have either a blown cylinder seal or a bad line (check the rubber hoses to the front and back brakes too) Repair the offending part and bleed the air out of the system... (remember to clean pads or shoes if they have fluid on them)... If you see no hint of leakage anywhere, then suspect the master cylinder... if you remove the master cylinder, check and make sure that it didn't leak fluid into the brake booster diaphragm (Brake fluid will destroy the booster)... as in any repair when you open the system (lose fluid), you will need to bleed out the air to restore function... hope this helps...;-)