I just replaced front pads and rotors for my 98' es300. Looks like the pads are not using the whole rotor surface. How aobut yours? rotor is brembo, pad is AK.

 

Insure the shims were installed properly, with the allignment "bends" facing away from the disk. Stainless shim to the outside. This refers to the inner and outer pad shim sets..

 

No, pads do not contact the entire rotor surface.
Get some high-temp spray paint (Aluminum / Silver) & spray it on the rotor hat, out onto the rotor surface. (Do not put the rotor in the oven, it'll get hot enoguh to cure itself.) Once dry, install. Look at how far out the paint goes, then go drive around the block.
You'll come back to find that the rotor has scraped a perfect circle out on the rotor. That's how far the rotor contacts.


^^^ That also keeps your rotor hats from getting rusty & nasty looking for years! Sorta matches most silver / chrome wheels too.

 

OK, I followed the instructions here:

http://zeckhausen.com/bedding_in_brakes.htm

and did the bed-in today.

Looks like there is a ring of 1/8 inch outside and a ring of 1/4 in inside untouched on the rotor surface. In between there is an even layer of pads material now. Still Don't know why Lexus deos not let the pads to use all the rotor surface like many others do. Rotor looks better if using all the surface I mean.

 

Probably because they don't need too. Even the old, 92-93 brakes can activate ABS/lock wheels well over 60mph. I think you may have a little bit of a wrong impression. I've never seen any pad that extends all the way down to the rotor hat. There is always a good inch, or so, of rotor with no pad clearance.
Just trust me & get a can of silverish high-temp paint for $4-5 & give the rotor hat & some of the surface 2 quick coats. It'll stay pretty & anything else will stay clean from the pad contact.