I just bought a 2004 G35 Sedan with 123000 miles.
I have pretty much gone through the entire car.

The brakes are where I am at a loss.
I have turned the rotors, installed new pads on all four corners and finished up with pulling a quart of fluid through the system.
The car rides perfect without any shake.
When I apply hard braking the car immediately stops.
However, when I lightly apply the brakes I get a shake.
If I do it at 65-70mph the car shutters violently.

Any Ideas?

I am leaning toward ABS pump.
Is there a how to somewhere that will instruct proceedures for testing the ABS sensors?

Once this issue is corrected my car will be as good as a new one.

Thanks for any suggestions.

 

It sounds like the rotors were warped, possibly to the point that they were beyond repair by turning. Replacement rotors are relatively inexpensive ~$180 for a set of Centrics from rockauto so I would suggest exploring that route. Then be sure to break in those rotors properly to avoid warping them.

 

I replaced the rear rotors today.
Hopefully I can get fronts tomorrow.

Getting non-Kia parts in a small bumpkin town is difficult.
I had to drive 30 miles to the next town to get the rears.
The fronts are in a town 50 miles away.

There are two parts store which will be open Monday, I will try them, but I have low expectations that they will have infinity parts in stock.

I have gotten the shake pinpointed to the front right now.

I can not wait to have all the problems corrected with this car.
I can only imagine how fun the LF window motor will be.