2004 Nissan Armada brakes problems

Was driving vehicle 35 MPH slowed down to go around sharp curve. When vehicle drove around curve there were vehicles in front of us that stopped suddenly. Applied brakes and pedal pulsed and required alot of effort to slow down. Was unable to slow vehicle down fast enough and rear ended vehicle in front of us. Caused a 3 car pileup. The 3 passengers in our 04 armada suffered whiplash, the driver sprained her wrist and was out of work for 3 days because of accident.

Serveral issues, the main issue is the brakes, and rotors. @ 7000 miles, the rotors were turned, steering wheel was pulsating, service department turned rotors. At 11,000 miles, the sterring wheel resumed pulsating along with the brake, slip, and vdc light activated on the control panel. I was told by the service dept. My brake fluid was low, perhaps leaking and the brakes require changing at my cost, the warrenty does not cover the brake issue. I told the service dept.