I just bought a new Jeep Cherokee, and now I'm afraid to drive it. I hadn't gone more than a few miles when the brakes went out. I complained at the dealership, of course, and they checked it out. But they couldn't find anything wrong and as good as accused me of making the whole thing up. When it happened I still had a little stopping power but the pedal went all the way to the floor. What can I do? Something was wrong; it's not just my imagination.
I believe the service department handled your situation irresponsibly. Losing your brakes is about as dangerous as it gets, and should be treated as a top-priority problem.
They could have taken you out for a test drive and let you hit the brakes hard on wet or sandy pavement. That way you could have experienced what the anti-lock brakes feel like. It's a bit violent; and scary if you've never done it before. The pedal kind of drops, you'll feel a pulsation and hear funny noises when you lose traction and the ABS kicks in. If that's what you felt when you believed the brakes had failed, then case closed, it's simply normal operation. If the test proved the anti-lock brakes are not what you experienced, it's a different situation. Don't drive the car.
Tell the service manager to give you a loaner until the problem is fixed. At that point, the technician should get on the phone with the support engineers in Detroit. Chances are the manufacturer will recommend replacing all possible causes of the failure, including the master cylinder and the ABS assembly.
Don't let anybody tell you that problems like this don't happen to brand-new cars. That's when the oddest things occur -- right off the assembly line.