On a 97 Grand Caravan, 3.8 with traction control, the brake pedal goes to the floor on first pressure, you can pump it up, but will go down in time to the floor. There is no leaks, brake fluid is up where it belongs. I did have to add a little DOT3 fluid two weeks ago. Where should a guy start, master cylinder? There is no lights on and the ABS seems to be working when I was breaking on snow.

 

Air got into your system somehow. Try bleeding the lines first. If after a short time the pedal goes to the floor, you will be looking at the master to be replaced. This is assuming you are correct wit no leaks.

 

Get it up on a lift if possible and really check those rear brakelines closely. If there are indeed no leaks, then the master is the likely culprit. Make sure that when you are checking for leaks that you have someone rapidly and sharply stomp on the brake pedal. That will send a pressure surge and should make even the smallest leak show.

 

Up Date- It was the Master-Cylinder. Thanks Guys