This is giving me a headache.. at first I thought It was the front rotors thats causing the squealing. Since I have bad vibration anyway, I went ahead and changed the front with new brake pads. I changed it with powerslot slotted rotors and posi-quiet pads. The brake feels 100times better..but the squealing is still there. The squealing comes and goes, but its most noticable when Im riding the brakes in traffic or at a light....quite embarassing..
So now im thinking its the rear brakes that causing the squealing. Its really hard to hear where its coming from..I have drilled/slotted rotors/OEM pads in the rear..with about 10k miles. Im really clueless at this point. I dont want to waste anymore money in the rear if its fine. anyone having problems??tried brining it to the dealers previously, but they wont work on it since i ahve aftermarket rotors/pads..

 

Did you do the brake job yourself? Could it be that there is no anti-squeal on the shims?

 

I have similar set up but no squealing noise - front/rear slotted/drilled rotors, front aftrer maket brake pad (EBC pad with integrated anti-squeal shim), rear OEM brake pad.

Does you posi-quiet pad use the separate shim like the OEM front pad? When I had my OEM front pad, it made loud squealing noise when car is in slow stop. Dealer replaed the shim, it was good for a while, but squealing noise came back.

 

its a different shim that came with the posi-pads..
so i went for a drive and try to pinpoint where the sound is coming from. its definitely coming from the right side, but hard to tell if its from the front or rear. i guess ill have them check out the rear next weekend.

no i didnt do the brakes myself, it was done at a reputable shop..camber toe on merrick road in Long island.

 

I had my rotors de-glazed at the dealer and the squealing went away.

Brake squealing/squeaking at very low speeds under light brake application is one of the more common annoyances with the IS. De-glazing every 30K miles or so will keep the noise at a minimum.

The service was done under warranty at no cost to me. I don't know how much the service costs on its own.

 

Bed, and then operate, the brakes properly and they don't get glazed in the first place

 

so bought it back to the shop, narrowed it down to the front passenger side and its ridiculously loud now when im easing on the brakes. Its more high pitch then ever.. he's saying that Im glazing the rotors and causing a mirror finish.. but i dont even race or stop hard enough to cause such an effect. sigh, I dont know what to do at this point. I'm looking at the rotors, while it does have a little mirror look to it, the crosshatching is still there. IMO, i dont think its what's causing the sound. and that fact that its on one side too makes me think that they fked it up on that side and not the other. I think im just gonna go back to OEM rotors and pads and be done with it. sigh.. any suggestions?

 

Yep this is correct. This is exactly what I was told when I brought my car in for squealing brakes. I did not "bed" them properly. I actually did not know what it meant to "bed the brakes" prior to this appointment. Fortunately I won't be making the same mistake a second time.

 

Did you "bed your brakes" properly as Kurtz discussed? If not, and if your rotors are glazed over, that's probably the problem.

http://www.zeckhausen.com/bedding_in_brakes.htm

You might as well de-glaze them anyway and see if it solves the problem or at least diminishes the noise. If the noise is diminished but not completely reduced, you'll know that the squealing was partly due to glazed rotors. If the noise is completely eliminated by deglazing, then you'll know that glazed rotors were the primary problem. If the noise isn't reduced at all, then it's something else entirely.

Regardless, you're going to have to deglaze your rotors anyway and see what happens in order to know how to proceed. It's going to be a process of elimination.

 

Well, this morning I decided to tackle the problem on my own. Jacked it up and looked at the pads... Freaking found out that they forgot to put the shims in!!!!! It was just bare pad against the pistons..no lube at all!!! So I added some lube from auto zone.. I'm gonna yell at their asses tomorrow about it. I checked the rotors,they r still smooth with crosshatching, very unlikely that the sound was caused by glazing...anyway, after the lube, went for a test drive , no more squealing!!!!! Lesson of the day, when u want domething done right, do it urself!!!btw,anyone know where I can get just the shims?

 

Your local Lexus dealership will have them. Sewell Lexus, a CL vendor will have them. I looked at 08 IS350 shims and they (Sewell) had them priced at $45 for a set. This seems high for 4 very thin, shaped pieces of metal. Try your local auto part store to see if they have them cheaper than what the dealership charges.

 

yea, i checked out sewell..i ended up getting another set of pads for less then the set of shims sewell is selling.. its ridiculous for a set of shims to cost as much as a set of pads. anyway, will install this weekend once i get them.. i should be able to get rid of the squeal once and for all!!!

 

Did you yell at the shop for being IDIOTS yet?