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Chris (aka - Moose)
Chris (aka - Moose), Technician
Category: Lexus
Satisfied Customers: 47693
Experience:  16 years of experience
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My 2001 Lexus GS300 ABS booster (brake master cylinder)

Customer Question

My 2001 Lexus GS300 ABS booster (brake master cylinder) keeps making noise. It started three years ago and never stopped. I have researched for a while and seemed no solution except replacement. It's not worth it for the cost of parts and labor. I did some experiment to unplug the surrounding power connectors to see if the noise can be reduced or gone. So far I found one connector can be unplugged without losing brake control. The pump is still making noise but with lower rate. The ABS/VSC/VSC OFF three yellow lights and RED break light are on. Also the long high pitch warning noise can be heard too but not often. Does anyone know how to get rid of this pumping noise besides the whole unit replacement ?
Submitted: 1 year ago.
Category: Lexus
Expert:  Chris (aka - Moose) replied 1 year ago.

Welcome, I'm Chris (aka Moose) I prefer working afternoon till just after midnight.

Sorry for the long delay, I got a late start today and have just worked my way down to the bottom of the list where you are. I am going to get a late start tomorrow as well. I feel like I can help on this concern if help is still needed. Please reply and let me know

Customer: replied 1 year ago.
Hi Chris,
I am still interested in solving ABS noise problem. These days I am having bad cold. I estimate one week rest should be enough to continue. When I am ready I will resume from here. Thanks.
Expert:  Chris (aka - Moose) replied 1 year ago.

If you are wanting to disable the ABS to stop this noise but your fine with it not working and the warning lights on then you would need to disable the ABS. To do this you would need to remove the ABS fuse 1 and 2 under the hood.

If you're confused on what to do now or later. You have already been charged the full question value. It's now time to compensate the tech that helped you. The only way I can continue to work here and help customers is by getting rated. If you're not pleased yet or plan not to rate me. Let me know so I can help more, close the post, or opt out. Please let me know if you're pleased with my help.

Thanks Moose.

Customer: replied 1 year ago.
Actually I have tried numerous ways in the past to disable the ABS pump noise. The system just prevented me to disable ABS completely. As the photo I attached, the power connector is disconnected. It will give me less ABS noise but in every several minutes the long high pitch warning noise will come out. That's very annoying too. I also tried your suggestion of #1 and #2 fuse fuse unplug. The car will be undrivable due to power brake loss.
Expert:  Chris (aka - Moose) replied 1 year ago.

Removing the fuses just kills the ABS and traction control. The base brake system will still work.

Customer: replied 1 year ago.
Are the two fuse blue and pink one ? Blue is ABS motor and pink is Track motor.
I did unplug these two fuses but it still gave the same result just like disconnecting the power cord as photo.
Expert:  Chris (aka - Moose) replied 1 year ago.

I do not know the color of the fuses, just the name, number, and amperage. The repair guides are not in color. With no power to the ABS pump and module. If your still getting a noise from the ABS pump area then the noise is not being caused by the pump since there is no longer power to it. Can you try and touch the part making the noise.

Customer: replied 1 year ago.
I am not sure the noise source is only from ABS motor. The apparent noise is from the cylinder. I can feel it when touching. Also my foot can feel it when break pedal is pressed. Its pretty loud inside and outside of the car. You can hear it from this youtube link. The noise is at the last moment of this short video.
Expert:  Chris (aka - Moose) replied 1 year ago.

If you unplug the wire connector to the cylinder doing this will the noise no longer occur?

Customer: replied 1 year ago.
Four power connectors connect to the ABS assembly. From the look I can't tell which one is doing what. Only thing is I kept trying to unplug different connectors to see what will happen. The best unplug one is on my photo sent to u. It reduced the noise frequency but a new long high pitch warning noise comes out even though break function seems OK. Also break red light, ABS/VSC/VSC OFF yellow lights are on. It seems to me the ABS pump getting power from different sources not just one. If a detailed ABS repair document exist, it might be helpful.
Customer: replied 1 year ago.
By removing ABS and Track Control fuses, the car sends out continuous high pitch noise. The break doesn't work.
Expert:  Chris (aka - Moose) replied 1 year ago.

I think I have done all I can do form here not seeing the vehicle in person. I am going to opt out and let another take a stab at this. Best of Luck.