YviE

iTrader: (3)

Actually, you might want to consult another mechanic. The buzzing sound is normal really. It's the pump building up pressure in the nitrogen circuit. However, it should not be pumping all the time. It is normal to pump after long braking or a certain time without braking. Yes, it also does it for a couple of seconds on start-up. Normal too.

Try and get the error codes, they might give a more precise idea of the problem.

Jaik

Yeah its not the noise itself that is strange, because it does have to build up pressure, its the rate at which it looses that pressure which is the cause for concern.

shurian

iTrader: (9)

I got brake master cillynder in good working condition of GS400, will let it go complete with assembly and etc, pm me

iRyan

iTrader: (7)

I just had this issue on thanksgiving day....change the whole unit...from the dealer it will run you about 1700 or a little more but go on car-parts.com and you will find some salvage yards that have it for cheaper...I got lucky and found a guy with a 2003 one for 200 and it only had 80k miles...I changed it and it works like perfect. Don't listen to anyone and get rid of ABS. Just get it fixed....go on the site car-parts.com

talexus

thanks for the site. sorry i don't have much knowledge about this but if i buy the Brake master cylinder, do i also need to buy Brake booster and assembly? my mechanic mentioned i need everything replaced and he can't even find the parts

thank you
your help is greatly appreciated

FrankT

The BMC is a all in one unit for our cars with abs modulator.
It is electronic as opposed to vacuum assist.

Like others have said, find a better mechanic.

YviE

iTrader: (3)

FrankT is right, you can't get rid of ABS as it's one unit....

iRyan

iTrader: (7)

Correct...it's on big unit all together and make sure it has the black computer module on the side....

talexus

will a Brake Master cylinder from a 98 Lexus GS400 fit on my 99 Lexus GS300 ?

thank you

YviE

iTrader: (3)

Yes it will, but it's better to go with a 01-05 BMC.

movaaa55

Hey im in need of help asap. I have a 99' gs300 and my BMC is making squeaking sounds like its trying to pump (it is really loud). and then my ABS, VSC, BRAKE, and VSC/off, lights are all on and has a loud continuous beep that goes on for up to 20 minutes at a time. Only when the effects are happening do i feel a slight squishiness to my brakes for the first inch of push. my mechanic said the same thing as above, hes quoting me 200 for installation only and says the part is 1400.

Is their any way i can fix this for cheaper?

and I heard that the 01-05 part wont work unless i get a new sensor for it, any idea where i can find that sensor and how it installs?

btw i live in dallas, tx if anyone here knows how to put it on for cheaper. Thank you sir!

-btw i can upload a video of what happens if it helps, just ask!

movaaa55

how much? and what year+miles? thank you

boltfan

Any updated information on this topic, especially used parts and what years may be compatible?

Dallas area.

Thanks

ls400beave

This is a great thread. I am having issues with my MBC on my 98. My brakes have a slight squishy feel when stopping from fast speeds and is also makes you press more firm on the brake pedal to stop in slower traffic. I also hear the electronic pump (buzz noise) coming from master cylinder from time to time especially in stop and go traffic. Although I have NO warning lights on, it does concern me. From what I read you need to replace the whole unit. It is the master cylinder + a abs brake booster. I am hoping to find one used working one. I just got the whip in April and not sure it the electronic pumping noise is normal or not. For both parts at the dealer it is $2400 and is rediculous..

Mosca

Just have had this problem occur too. 98 GS300 and I don't like to mess around when it comes to brakes.. Anyone?