Squealing Sound While Driving. Brakes Need Replacing?

[FZ6 Dude]

Hello,

I was driving my wife's 2006 RX330 yesterday when I noticed a squealing sound was present, almost always while driving and while braking. This is only heard when the window is down. I am guessing that the brake pads are near their end as I have heard a similar sound from my old Honda Prelude when it needed new pads. (I still am not sure why this is heard if you are not applying the brake .......) Anyway, with only 31k on the vehicle, as long as the pads still have some life to them, and the rotos are not scratched up, would I be doing myself a disadvantage by only replacing the pads and not the rotors? If so, wouldn't it be best to have the rotors turned, if they still do that kind of thing?

I am confident that the caliber is not stuck as after driving 25 miles or so, A- I did not smell anything lawful. B- The wheels were not hot to touch.

Lastly, I have done some searching on the site and have seen suggestions for brake pads everywhere from Auto Zone ceramic to Akebono ceramic brake pads. What do you guys (and gals) think?

Thanks.

[RX in NC]

First of all, it is unusual that your brake pads are nearly done at only 31,000 miles. The factory pads are good quality semi-metallic, and we typically get more than 80,000 miles out of them with my wife as the primary driver. You may want to check to see if your pads are dragging against your rotors even when no brake pedal pressure is being applied. If that is indeed happening, it will greatly reduce the lifespan of your pads and may very well be the reason your pads are nearly done at only 31,000 miles. Often the cause is the emergency brake tightening up on the rear pads and wearing them out prematurely.

About ten days ago I replaced the rear pads on my wife's 2004 RX330 AWD at just under 88,000 miles. The rotors are clean and unscratched so I chose not to turn them. Whenever you turn your rotors you are reducing their lifespan, so I'll turn them only if they are not still smooth and unmarked. I researched brake pads very thoroughly and decided to go with a set of Wagner ThermoQuiet organic pads. As the name indicates, they are noted for being nearly silent, they create next to no brake dust, they are not nearly as hard on your rotors as ceramic pads are, and they should deliver at least another 75,000 miles of service in this vehicle. She has put about 200 miles on the RX330 since I replaced the rear pads, so they are now well-seated and completely silent. The rear rotors remain smooth and unmarked. Her factory front pads still have 30% to 35% of pad life left in them, so there is no need to replace them yet.

I also put a set of these ThermoQuiet organic pads on my wife's previous 2000 RX300 AWD at about 82,000 miles in the summer of 2005. The current owner now has about 143,000 miles on that vehicle and he tells me that the pads are still going strong and don't make a sound, just as advertised. His wife is the primary driver.

So to sum up, if your rotors are clean and smooth, don't waste your money (and their lifespan) by turning them. Do some research on the Wagner ThermoQuiet organic brake pads. I think they are the best choice in this particular application....

[FZ6 Dude]

Excellent summary. I will pull off each wheel today to take a look at the pads and see if they are worn out, and to see if something else is going on.

On a side note, I do notice a "slight" pulse feel when I apply the brakes. If this is indeed the rotor, wouldn't I need to turn it to get rid of this? How else can I tell if the rotors are warped, without seeing obvious scratches on them from overly worn pads coming in contact with them?

Thanks.

First of all, it is unusual that your brake pads are nearly done at only 31,000 miles. The factory pads are good quality semi-metallic, and we typically get more than 80,000 miles out of them with my wife as the primary driver. You may want to check to see if your pads are dragging against your rotors even when no brake pedal pressure is being applied. If that is indeed happening, it will greatly reduce the lifespan of your pads and may very well be the reason your pads are nearly done at only 31,000 miles. Often the cause is the emergency brake tightening up on the rear pads and wearing them out prematurely.

About ten days ago I replaced the rear pads on my wife's 2004 RX330 AWD at just under 88,000 miles. The rotors are clean and unscratched so I chose not to turn them. Whenever you turn your rotors you are reducing their lifespan, so I'll turn them only if they are not still smooth and unmarked. I researched brake pads very thoroughly and decided to go with a set of Wagner ThermoQuiet organic pads. As the name indicates, they are noted for being nearly silent, they create next to no brake dust, they are not nearly as hard on your rotors as ceramic pads are, and they should deliver at least another 75,000 miles of service in this vehicle. She has put about 200 miles on the RX330 since I replaced the rear pads, so they are now well-seated and completely silent. The rear rotors remain smooth and unmarked. Her factory front pads still have 30% to 35% of pad life left in them, so there is no need to replace them yet.

I also put a set of these ThermoQuiet organic pads on my wife's previous 2000 RX300 AWD at about 82,000 miles in the summer of 2005. The current owner now has about 143,000 miles on that vehicle and he tells me that the pads are still going strong and don't make a sound, just as advertised. His wife is the primary driver.

So to sum up, if your rotors are clean and smooth, don't waste your money (and their lifespan) by turning them. Do some research on the Wagner ThermoQuiet organic brake pads. I think they are the best choice in this particular application....

[RX in NC]

Yes, a pulse in the brake pedal could indeed be an indication of one or more warped rotors, especially up front. And yes, they'll have to be turned to fix the warp (assuming they are still within tolerance).

A great way to find out at no charge is to go to a local Midas franchise and ask for their free brake inspection. You'll get a full report of where your brakes stand and you are under no obligation for them to effect repairs. Our local Midas shop does great brake work, guarantees the parts for the life of your vehicle, and the long-time owner is extremely knowledgeable on brakes for just about any application you can name. He made me aware of the Wagner ThermoQuiet organic brake pads a few years back and highly recommended them. He turned out to be absolutely right.

On a side note, I had Lexus replace the front rotors on my wife's current 2004 RX330 AWD using Technical Service Bulletin TSB 004-04. The original factory rotors were of inferior quality and had a tendency to warp. This warranty work was done in May 2007 at 48,200 miles. We've had no rotor problems since. I assume that your 2006 model was built with the improved rotors, but perhaps not. You should make a note of this and check with your local Lexus service department.

Good luck....

[blk_on_blk]

A few things to add, on newer vehicles, the rotors are designed and fabricated lighter and thinner... and it is not recommended to 'turn' or reface newer (like post late 1990's vehicles) rotors. It can be done, but it increases the potential of warpage. Best practice is to either just replace your pads if your rotors are clean, smooth, and straight... or replace both pads and rotors.

Also, if your rotors were clean, smooth, and straight (and it sounds like one is slightly warped), then you'd want to stick with the exact same type of pad you are currently running to prevent squeal and noise after replacement. This is because brake pads 'seat' themselves into the rotor, meaning depositing a little bit of brake material into/onto the surface of the rotor... a fine 'skin' of it if you will. Changing to a different type of pad without deglazing the rotor could make an interference of material and cause noise, if not reduced braking efficiency. If you want to change type/brand of pad with the same rotors, then you'll want to knock off and de-glaze the rotor before you put the new pads on. You can do this with a rotory sander or grinder (preferably a grinder with a flexible disc). Move the grinder from the center of the hub out to the edge, do this sequentially around the each face of the rotor. It will make all these slight radiating scores in the surface, but it will take away any squeal issues you might face with your new pads, plus it gives a relatively clean surface for the new pads to seat into.

FWIW, I changed out our front pads/rotors to Akebono ceramic pads and Centric rotors (Centric rotors actually have the surfaces with the radial grinding streaks prefabricated in them). Since the repair (several months ago) the braking has been noticeably stronger and smoother from day one and continues to be excellent! No noise, no fading, no pulsing... just good strong braking.

Lastly, make sure you pull out, clean, grease, and reassemble the slide pins on your calipers before you replace them. You'll want to pop off the dust boot, slide out the pin, clean the pin and receiver hole, and put a nice layer of clean high-temperature bearing grease into the assembly. Reinstall the dust boot and check for easy sliding. There is a lot of heat generated in brake calipers, and the grease tends to kind of gum up over time. This quick cleaning/regreasing will ensure even clamping by the caliper for many miles to come!

[FZ6 Dude]

Thanks for all the information.