What else could it be?

I just replaced the master cylinder on my 03 ford focus because all of sudden there was no brakes. I bleed the master cylinder on the car and then went to bleed all four wheels. Now when I press on the brake pedal it travels about 75 percent of the way before starting to stop the car. There's also a "whooshing" sound when I press on the brake pedal. It only does this with the car on. With the car on the brake pedal is hard as rock and I can hear the calipers clamping to the rotor. From here I'm at a lose. Any information would be greatly appreciated.

Sounds like there's a problem with the vacuum brake booster.

Check the brake vacuum booster. Sounds like the diaphragm may be busted. Can also be the hose needs replacing.

Did you prime the master cyl. Before you put it on?

Bleed the brakes again that might be all it needs

"I just replaced the master cylinder on my 03 ford focus because all of sudden there was no brakes"
Obviously you have introduced a ton of air into the system because you didn't bench bleed the master cylinder. It's impossible to do it properly on the car. There's now so much air in the system you may need a pressure bleeder to push it all out. Have the car towed to a shop that has a pressure bleeder kit and ask them to bleed the system, it shouldn't cost that much.
As for the brake booster suggestion, a bad or leaking booster just makes the pedal harder or seem better, not worse. The whoosh sound is just what it does when there's no resistance and it drops fast.

You never hear the calipers clamping. Take it to a mechanic… Oh that means call a TOW TRUCK because it is undrivable right now because it is unstoppable.

So the old master wasn't bad. Did you pull the rear drums? I'm assuming drums here on a cheap ford. Check the shoes and their travel. Adjust them if needed. Check all hardware. Check all rubber brake lines for bulging.

Loosen the brake pipe where it comes out of the master cylinder, just pump the pedal until you can't see any bubbles. ( preferably get someone else to pump the pedal white you watch and then tighten the pipe back up. Then go around the rest of the wheels and bleed each one until you see no air.

Read about bleeding a master cylinder.

You may be able to do it on the vehicle, but you must disconnect the brake lines and connect 2 temporary lines to pump into a can, and then you can pump it with the brake pedal. You're supposed to "bench bleed" the master cylinder before you install it. I never saw one without instructions.

Best if you have a helper to squeeze the hoses. I use clear aquarium air hose when I bleed brakes, so I can see the bubbles.

There's more to proper mechanic work than unmounting and remounting things. There are endless procedures used when properly repairing cars.

-General automotive mechanic since 1972

Wrong brake fluids