Posted 17 December 2003 - 01:31 AM
I agree with Rush48. This car does not have a vacuum assisted brake booster, but rather an electrical pump to create hydraulic brake pressure. Owing to the system design, I would assume that it is normal, yet bothersome. Why would Lexus, the king of the smooth and silent, utilize such a noisy, obtrusive system in their vehicles? Beats me!
On the other hand, here is where I too have a problem. When this pumps kicks in, usually after using the brakes every 5th. or 6th. time, it can make the car lurch forward a little. For instance, if you're moving along going say, 65MPH, and you touch the brakes....if the pump kicks in at that particular moment, the car will lurch forward slightly and then smoothly brake afterwards.
Can anyone else verify this operation? On a side note, if your pump happens to be quiet enough that you don't actually hear it, you can verify that it is kicking in when you hit the brakes. The pump draws 27 amps of battery current and will cause the headlights to dim noticibly when driving at night. You can also see this happen when you are stopped if you repetedly depress and release the brake a couple of times to cause the pump to kick in.
So, the question is...is the lurch normal? Good god, I hope not. It sure is annoying.. But on second thought, I don't even want to think about what it will take to fix it if it isn't. My dealer cost is about $1600.00 for the ABS pump assembly. Yet they offer me no assistance to verify if there is actually a problem.