Brake trouble

[Jordan]

Mods, im not sure if this is in the right spot, if not, move it please.

I have a 1997 chevy 1/2 ton 1500 P/U.

Went to get the oil changed about 4 days ago, the guy put new brake fluid in the reservior, cause he said it was a little low.

Problem: When I push the brakes, I have to pretty much stomp them to the floor to stop. It sounds like an air leak coming from inside the cab.... just a constant psssssssssssssssssssssssssssshhhhhhhhhhhhhhhhhh. When I finally get stopped, the truck starts sputtering like it wants to die out.

What I've done: Looked at the reservior to make sure there is still fluid and also made sure the cap was on right along with the seal.

My Question: Is there air in the lines ??

I need to get this fixed....