vlad_a

If the thump happens after going in reverse, it is normal - brake pads shifting.

plusONEran

iTrader: (2)

the brake actuator needs to be replaced.... its covered under warranty still 4 years /50k miles

corradoMR2

Correct, this is the response I got from my dealer when I brought this to their attention. They also said there is no safety concern. I live with it and doesn't really bother me since hitting the brakes on reverse is 1% of my driving time and forward braking - no issues.

svidas

My 2010 RX450h is having the brake actuator replaced now since the "sqwack" sound meant to them a bad actuator. I was in previously and they just bled the brake lines. Luckily it is still under warranty since the part looks to be quite expensive.