Problem After 2010 Is250 Awd Brake Pad Install

[turboflgrl]

I have a 2010 IS250 AWD and had my Dad change the front brakes. I now have the Thermoquiet Ceramics from Advanced Auto. I've had my Dad install these on a 2 previous Toyota's with no problem. However, when I went to take it for a test drive, I heard a quite audible hissing and squealing coming from both front wheels - the car did not have these issues before so I know it's not coming from my engine. We decided to take it for a drive around the neighborhood and it continued. Constant hissing and squealing (makes a "whoosh whoosh whoosh" noise in addition to the loud squealing) while I'm actually driving - not due to pressing the brakes.

Any ideas? I apologize that this is my first post. I appreciate any help you can offer!

[1990LS400]

Perhaps the brake rotors are unevenly worn and need to be machined. Sometimes brake pads simply need to "bed-in" - here is a discussion: http://zeckhausen.com/bedding_in_brakes.htm

[turboflgrl]

Well... that was easy. Turns out the aftermarket shim was the culprit. The ones that come with the Thermoquuets do not fit. We fished the old, undamaged ones out of the trash and the new brakes are working great. So odd since both cars previous to this fit just fine when replaced.

Anyone know if Lexus sells just the shims? Otherwise I'll be switching back to Lexus parts after this.

Thanks for taking the time to respond!

[James Horning]

Yes they sell shims independently and on some models greatly enhance brake feel and noise reduction.

If you rotors have a groove at the outer most circumference replace them .

After market rotors will do just fine, rock auto , tire rack etc.