CrazyHawaiian

I recently experienced something with my 1990 LS400 and it has me a little confused about what to do. The car has around 160K miles and its been regularly serviced. I was driving on a Highway with a somewhat steep slope downhill. All of a sudden the car would begin vibrating/shuddering violently whenever I would press the brakes. It caught me off guard because of how sudden the behavior of the car changed. One minute it was fine, next minute it was crazy. I could feel the vibration/shuddering through the steeringwheel and the shifter. It would only happen when pressing the brake (ammount of pressure didnt matter, hard or soft it was going crazy). I pulled over and let the car sit for about an hour to cool down. I've had vibrations/shuddering while braking happen in the past with other cars, usually it means the brake rotors are warped. Well, after letting the car sit I drove back home and everything was fine. I've been driving it for a few days now (even on hills) and everything is fine. So this is what confuses me ... how could the car act so screwed up but all of a sudden its better again? From my experiences problems with warped rotors happen gradually and they don't get better on their own. This one happened super fast and then next thing you know its fine. Not sure what to think! I'd like to perform some preventative maintenance but I'm not sure where to start. My friend said its possible the ABS was pulsing when its not supposed to, has that ever happened to anyone? The problem has not happened again so it appears to be intermittent, making it hard to troubleshoot. If I do go the rotors route I'm gonna replace them myself, but would suck to replace em and then it happens again, figgured I would ask some lexus people. Thanks!!!

PureDrifter

iTrader: (10)

check tire pressure, could have a bubble?

dinh626

I dunno but heres what happened with mine. had vibration when braking replace front rotors and brake all better then came back....rears then needed changine, new rotors and brakes....no more vibration. good luck.

Suneet

I have the same issue with my LS400. Vibrations at high speed while breaking. I'm pretty sure my front rotors are the culprit.

steveski

My culprit was actually the rear rotors. I was really surprised that after I turned the front I still had a slight vibration. Then after I turned the rear rotors all gone.

CrazyHawaiian

When the problem happened to you guys was it consistent? Or did it go away for a while and then come back or something? Because whats confusing me is the car drives perfect now, no vibrations at all.