Kia sedona noise

We have a 2006 KIA Sedona with 50,000 miles. It is a fine car. But it makes a weird noise infrequently. At low speed, it will make a ?crunch? or ?grinding? sound. It almost sounds like the front wheel is hitting the body of the car. The driver of the car can feel the car vibrate with the gas pedal. It usually happens when the driver press on the brake pedal. The brake pedal will respond by rising or pushes back slightly towards the driver.

We have had all 4 brakes [disc] replaced and bought new tires. The car still makes the sound at low speeds. The sound happens infrequently ? maybe 2 times a week,

We thought it was the ABS system. With new brakes we are not sure. The car stops OK and handles fine in all respects.

Thank you for your help.