Brake Disc Pads problems of the 2003 Toyota 4Runner

I had issues with the brake pedals ever since 2-3 years into driving the vehicle. I have a 2003 Toyota 4runner and the brake pedal is not very responsive. I had the brakes, rotors and brake system checked and there are no issues. My biggest issue is with the brake pedal itself. I feel when I hit the brake, a gentle tap doesn't produce a response. Only a mild to hard step on the brakes would cause the vehicle to stop. Im very wary of this b/c I always have to hit the brakes hard to get a response. I feel the brake pedal is loose because it is not very responsive and does not respond to tapping. In fact, if I hit the brakes and the brakes drop one inch, there would be no brake response. I had the vehicle checked by Toyota dealer and they said its some sort of brake part that needs to be replaced. Upon replacing that part, I still feel the same looseness in the brake pedal. My most serious concern is that when I hit the brakes sometimes b/c I have to hit it hard, my vehicle feels like it's drifting. The wheels would go left and right and then go straight. This does not happen often, but when it does, it freaks me out. At freeway speed, when I hit the brakes, whether its light or soft, sometimes, the car just does the random drift. I feel its the result of a loose brake pedal and perhaps delayed response to the tires. I changed the brake pads and I had my brakes inspected often due to this issue.

- the contact owns a 2003 Toyota 4 runner. The contact heard a noise coming from the front brakes. The contact had to apply the brakes with great force for the vehicle to stop. The vehicle slid to a stop. The dealer's diagnoses was that debris in the rotors caused the noise. However, they were unable to diagnose why the vehicle could not stop without sliding. The front brake pads were replaced, and the rotors resurfaced. The failure mileage was approximately 900 miles. The contact has the repair order. The current mileage was 40,000 miles.