BayAreaLex

Hi guys,

A couple years ago I had the dealer install new brakes on my 2001 GS430 (resurfaced the stock rotors and used OEM lexus pads).

At that time I was using my Lexus as a second car and it sat in the garage for about a year with very little use. After I sold my primary car, I began daily driving the Lexus again. After a couple thousand miles, the rear brakes started to squeal badly... and I mean so badly that I almost can't drive with the window down because the noise was so piercing.

I took the rear brakes apart to inspect them. The rotors looked smooth and I didn't see anything obviously wrong with the pads. I hit the pads with sandpaper and lubed up the shims that contact the backs of the pads. It made no difference to the squealing.

I'm thinking about getting new rear rotors and replacement Wagner pads (#PD771) as I don't want to use the oem pads again after this experience. I have two questions that I am hoping you can help with:

1.) When using aftermarket pads, is it still recommended that I use the stock shims or no? It almost looks like some aftermarket pads have shims built into the back of the pad.

2.) Can someone confirm the part number for the rear shims for a 2001 GS430? Mine look a little beat up and if I'm going to be replacing the rotors/pads, I might as well replace the shims. The reason I am asking is because I see different part numbers referenced online.

I see 04946-53010
I see 04946-30071
I see others as well.

Anyone know which is the right part#? Thank you!

GS400V8

iTrader: (4)

1) Some higher end aftermarket pads have a medium density rubber backing for the shims. You wouldn't have to use the original shims in this case. Although, there is nothing wrong with the OEM pads, and I much prefer these my self.

2) The original pads themselves are - 04466-30161
Stock shims are correct in your post above - 04946-30071

I would recommend not only greasing the back of the shims, but greasing anywhere in the caliper where metal on metal contact exists between the main pin, the retainer clips, and the pads. Perhaps even wire brush, lightly sand, and clean these while everything is apart.

Even though these are "Brembo style fixed" calipers in the rear, there is movement between all of these parts when the pistons are compressing and expanding, just like the "normal style floating" calipers do up front. Any hang up, dirt, debris, or extra friction can cause noise and vibration.

You can let me know if you have any more questions and good luck! Respectfully, Ya'acov

BayAreaLex

Thank you very much for the reply. This is helpful.

GS400V8

iTrader: (4)

Of course! There is no matter

99 GS3

iTrader: (14)

If the noise is constant and not affected by pedal modulation do keep in mind the rear rotors also have a drum brake inside for the parking brake and could be a cause of rear brake noise as well if the pads are not retracting properly inside the drum.

burny

I use sil-glide on back of shims and the slide pins. Sil-glide holds up well.