My wife's highlander started getting some vibration when braking at highway speed. It was very difficult to determined if it was the fronts or rear cause I felt no real vibration in the steering wheel, break pedal, more so in the seat... a front to back pulsing, which would lead me to think it was the rear brakes.
All the brakes and rotors looked good, with plenty of meat left on the pads. I took my dial indicator out and check the rotors. All were within 1-2 on the scale except the front drivers which rotor which was about 5. So, I'm thinking..bingo.
so, my questions is, after replacing the front rotor should I:
1. replace the front pads or use the old ones that have lots' of life left
2. do I need to resurface the passenger rotor if I put new pads on it
I know this is a brand x, but the help would be appreciated.

1. Lightly sand the the old pads to give them a bedding surface with new rotor.
2. Rough up the surface of used rotor with sand paper to allow new pads to bed in.
I am not an expert. This is what I would do.
FYI: I am on my second set of rear new pads/rotors in past 30 days on '07 Highlander and still have brake squeal, so what do I know!!