Need help:
2005 LS 430, 189,000 mi. Los Angeles area: When braking, I hear a rumbling sound, Im pretty sure is coming from the rear of the car. Also feel a ‘pulsing’ in the brake peddle, and car seem to follow along with the pulses. Similar to a warped rotor feel. The brakes and rotors were all changed about 5,000 miles ago. I don’t feel any shake in the steering wheel.
It could very well be a warped rotor, but before I dig into that, I wanted to know if rear wheel bearings could be doing that, and how to check the rear bearings?
Thanks for any input.
Steve

 

I recently changed my passenger side rear wheel bearing (190k) due to a rumbling sound it was making, but it didn't cause any of the other things you mentioned. It made noise all the time and did not change at all when braking. It did get slightly louder when driving fast on a road that curved to the left. The best way to check a wheel bearing on these cars is to use an automotive stethoscope and probe the hubs listening for noise as you spin the wheels up to speed (30mph+). When mine went bad this would have been the only way to tell for sure since the wheel bearing was not loose at all and the wheel spun freely. But I didn't have a lift and did not feel comfortable spinning the wheels up to speed with the car on jack stands, so I just went with the best guess and luckily that was it.

In my experience, the symptoms you describe are always brake related.

 

jack the car up, and manually spin the front wheels to see what the bearings sound like.

 

The front has new bearings. The rear does not.
Thanks for the reply

 

Thanks for the reply. It does feel like a warped rotor, but they are fairly new, so I thought I would look for other remedies. Changing rotors is easy enough, Changing the rear bearings can be a stinker.
Thanks again.