XxGoKoUxX

anyone have a weird *** noise coming out from under their hood after about 15-30 seconds of shutting off their car? it's like something mechanical is pumping/draining outta the brake system area lol.... or maybe i'm crazy

Rider

Yes. I get that noise too frequently. No idea what operations are going on under the hood tho...

XxGoKoUxX

possibly the electronic braking system in the car lol..... i may call lexus and ask, just i'm extremely lazy atm

rominl

iTrader: (4)

yes, after the car shut down the brake pump will work for a little while. no biggie don't worry about it

XxGoKoUxX

thanks rominl, my friend who has a gs300 says he doesn't hear his go off, but then again he told me he doesn't sit in the car long enough to hear the noise lol...

does anyone know if there's a reason?

rominl

iTrader: (4)

i remember reading about it long time ago, something like the brake pump cycling through or something like that. it happens on all my lexus, gs400, sc430, is300, ls460l

one thing i notice is, when the car is running, if you look at the brake reservoir level, and compare it to the level when the car is not running, they are not the same (i think when car is shut off it's higher). so i guess the pump is doing something

lexus ASM

If your car has that happen all the time it means theres air in the system, the actuator motor is what you hear running and its trying to pressurize the system. When people bleed there brakes they normally leave huge pockets of air in the front lines. The only way to correctly bleed the brakes is with a scan tool that allows you to bleed each line separately.

The problem is you cannot actuate the motor manually when you bleed the brakes so you end up bleeding the line after the actuator not from the reservoir like its supposed to be done.

It is possible to do the rear lines by cycling the key to the ON position and applying the brakes while somebody open the bleeder screw on a rear caliper, the difference is the motor pumps the fluid rather than your foot... Not sure why this doesnt work for the front but it doesn't.

The noise should stop after a max of 40 seconds if it doesnt you need to have your brakes bled.
Hope this sheds some light on your noise...

whlkev

I believe this noise is mentioned in the manual.. if you any of you even bother to read it..

ReyRey305

iTrader: (3)

if u need to read a manual for a car then don't drive, lol

whlkev

then tell people to stop posting noob questions =)

*not directed at OP

XxGoKoUxX

thanks for shedding the light =]

my car doesn't do it for more than 4-5 seconds lol, this is the first car i've owned that has electronic braking and electronic throttle so i'm not 100% familiar with all the gadgetry in this vehicle, but i'm slowly learning

wgreene63

Whoever is telling you to ignore this noise or that it is OK is giving you bad advice. Eventually the noise will last longer and finally you will get a few warning lights. Namely, ABS, VSC, and Brake disc. Along with a brake malfunction message.
My GS460 started making the noise when I turned it off and it lasted for a few seconds. I checked this forum and thought, because of some of the posts, that this was normal, OK. Not!
The noise started lasting longer and longer. I started feeling it in the pedal while I was driving. I had the Lexus Techs bleed the brakes. No luck. They advised I needed to replace the actuator. Shortly thereafter the actuator failed. The braking response of the car changed dramatically. I actually put the car in gear and with my foot on the brake it still lurched forward.
Unfortunately my car was no longer under warranty and the replacement part was over $3000 from Lexus. I tried to get help from Lexus, they offered $350 and the dealership offered $150. Their cost for the repair was $3700. I was able to get the part for $2250 online and had a moonlighting Lexus Tech replace it for $300.
If your car is under warranty and this noise starts, insist they replace your actuator before the warranty expires. I assure you that the posters on this site that THINK the sound is normal will not offer to help you get your actuator replaced when it fails.

Mike

2008 Lexus GS460
Silver/Black/ML/Nav/XM/

XxGoKoUxX

To revive on the subject, have you sat in your car again and waited for the noise to go off now?

Now you've piqued my curiosity on whether or not this subject is normal, as almost everyone on here has heard the noise.

blue00

I have never heard it on my 2010, there is an electrical motor noise the instant i turn off the car, but that sounds like something in the steering locking rather than brake pump

lex-ative

The consensus is that it is normal.

Wgreene, I think yours was on the way out anyway, if there was a change in the duration of the sound. Mine sounds, and is the same length every time. The dealership should have notified me if it was an issue, since I doubt they would pass on the opportunity to make 3 grand if it was something of concern.....