Threxx

I have a 99 GS400 with 53,500 miles currently, and the full Tom's bracing setup (F&R lower chassis braces, F&R strut tower braces, & 6-pc rear suspension bracing kit.

Anyone have any idea what it could be?

It, as far as I can remember, only happens when I first put it into reverse. It happens in any situation... whether the car is warm or cold, whether the temperature is warm or cold.... doesn't matter. I can go from park to reverse and start backing up, or I can go from drive to reverse and start backing up - and of course when I go from one gear to the other, I have the brakes on. But once it's in reverse, I let off the brakes and start going backward slowly... however, as soon as I barely tap the brakes, I hear a very audible popping noise (loud enough that a couple of other people who care nothing about cars mentioned it). It almost sounds like a small rock hitting the underside of my car.

I guess it's not so much that I can't stand the noise, as much as it is I don't want it to be indicating something that needs to be fixed and not realize it.

bscottj

It might be the sound of the brake pads hitting the stop on the caliper after changing direction and sliding a little bit. Are you using stock pads and calipers? I think Lexus has a solution for this if you report this issue. I think the solution involves greasing the areas so the pad slides more easily (and quietly) when changing direction and applying the brakes. I thought there was a TSB on this, but not sure. Anyone?

braheem

iTrader: (4)

I had the same sound on my 100% stock 98 LS400, changed the brake pads and it was gone.

ligflava

Threxx: I've had the same problem in my GS. In fact, i have the warranty note right in front of me. "Cause: Excessive clearance in brakes. Correction: Removed FT and RR brakes and calipers. Removed fitting kit and lube w/ brake glue. Part # Lex 08887-80609"

All fixed and that was about 3k miles ago. hasn't returned yet...knock on wood.