kfinnie

I own a 2005 LS430 with 49,000 miles. It was perfect... until last Monday.

Two blocks after leaving the Lexus dealer, where brake pads on all four wheels were replaced, I rear-ended a car waiting at a red light! I had been distracted... and when I saw the car ahead, I slammed on the brake pedal. The ABS did not engage, there were no skid marks and the air bag didn't deploy, even though I hit the other car at ~30 mph. There was 2.5 +/- 0.5 seconds from when I hit the brake until impact. (I'm a calibrator so this is something I'm good at estimating)
It felt like I was driving a car that didn't have power brakes, let alone assisted ABS brakes!

Prior to this brake repair service, the braking was always positive and the ABS would engage whenever I was even a bit heavy on the brake pedal. I've owned the car for about 8 months and have put 20,000 highway miles on it. I've previously owned 3 GS's and an LS, so I have plenty of experience with Lexus. I think that if the ABS had engaged, I might not have hit the car.

What could have gone wrong during the servicing?

The insurance adjuster is going to look at it on Friday but I' don't think that his interest will be to identify if something was done/not done during the brake repair but just what will it cost to repair the vehicle. Additionally, the car is at a certified Lexus auto body shop that is owned by the same group that owns the dealership.

What do I do?

Lavrishevo

iTrader: (1)

Really sorry to hear that. I hope everyone is ok. If the brakes did not lock up then the abs was most likely working. New brakes need to be broken in and do not have the same stopping power until they have been beded.

Jabberwock

Sorry that happened to your car but glad that you were not injured. It is possible that you may have had some air in the brake line - did you notice a soft pedal at all? Did the pedal go to the floor?

AlexusAnja

sorry to hear, hope it's not totaled. If ABS didn't kick in, wheels didn't lock up and skid, then brakes did what it was supposed to do and you just hit someone. You said you were distracted, so perhaps you were closer than you thought. Still... bummer...

Tom57

Did you look to see if there was there any brake fluid on the street, around the calipers, etc.? Is the brake fluid reservoir filled to mark?

LiCelsior

iTrader: (32)

sounds like the pads werent fully bedded yet, theres a layer of glaze that are sent with the rotors to prevent them from rusting. from what it seems, i dont think the dealer had performed any brake in test periods for this.

Coulter

I think we found the culprit to why the accident really happened.

Could it have been the brakes weren't at their peak "grip" because they were new? Possibly, but there's also a myriad of different brand pads that have different braking performance, some better than others.

You can't really expect a repair shop or dealership to drive around a customer's car for a few days until the pads and rotors are at the peak in stopping power.

It would be a long shot lawsuit in my opinion. You would need something really dramatic like a brake line that had come undone and the pedal went to the floor without stopping, etc.

kfinnie

I concur that surface protection on the pads was the critical issue and that it was worsened because all pads were replaced at the same time. Had I driven 100 (or maybe only 10) miles before the emergency stop, I'd probably only have had a close call.

The appraiser got in there early. It was 10k of damage.

So, learn from my experience, don't ever replace all four sets of brake pads at the same time as you will never know when you will need to make an emergency stop.... especially with such a beautiful automobile as this.




To those who asked, there was no brake fluid dripping and there was no yield in the brake pedal. I've experiences that one in the past.

StanVanDam

I think the likely cause is because this was immediately after changing the pads. Some possibilities:

* Whoever changed the pads messed up and got grease on the pads or rotors, and normally it's not a big deal since it burns off after some in-city driving, but for an emergency stop on the first use, this is a huge error.
* Pads/rotors had some sort of protective layer on them that gets burned off after first usage and/or during bedding in, and you have lowered friction during this time.
* Prior to first use, the pads and pistons weren't as close to the rotors as possible. Even a fraction of a millimetre off could be enough to delay your braking time or cause your wheels to brake at different speeds and/or start times. Using the brakes with moderate force once should set the pistons to where they should be - holding the pads extremely close to the disc.

The Brake Assist feature exists on my 2002. I felt it kick in when a cat ran in front of my car once, and once when someone changed lanes into me. When you do a fast panic stop, the Brake Assist applies additional braking pressure for you. You can feel it suck the brake pedal in and apply maximum stopping force - it stops the car very quickly.

If you didn't feel the Brake Assist kick in, it is possible you braked too slow or not hard enough. I've braked hard lots of times without it kicking in - it needs to sense a panic stop: a hard brake that is also fast, or within a very short time of last touching the accelerator.

I wouldn't think that the Brake Assist relies on feedback from the wheel speed sensors - it should just rely on your brake pedal force. If Brake Assist takes feedback from the speed sensors, then the lack of friction in your pads effectively disabled the Brake Assist.