Robotic brake noise...part 2?

[titan2782]

There is another thread on this, but no one posted an audio file. I've been noticing this noise in the last 2 weeks and it's happening all the time now. when the brakes are applied while the engine is at low speeds or idle (may occur all the time, but can't tell due to road noise) there comes a robotic servo noise that will continue for 2-3 seconds even if I take my foot off the brake. It happens EVERY time i put pressure on the brake pedal and if I pump the pedal, I can get the noise to continue on forever.

I'm at just under 45k and i've only heard this noise in the last few weeks so it isn't "something these cars do". It's very noticeable inside the cabin with windows rolled up and even when music is playing (low volume).

Ideas? Maybe vacuum issue or low fluid? I haven't investigated as of yet.

Audio 1: https://www.dropbox.com/s/31ws6avmbj...oice%20002.mp4
In a drive thru (kind of noisy outside)

Audio 2: https://www.dropbox.com/s/e80ksay5p1...oice%20003.mp4
In my garage with car running

Have to turn the volume up.

[kobowm]

They are called electric pumps...... They pump brake fluid to the brakes.... Its 100% completely normal.

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[titan2782]

No, it isn't normal. During initial start up from 1 mile until ~44k miles the robotic noise happens during and only during the initial key switch. Now it happens both when I press the pedal AND release and does not matter if the engine is running or not.

I topped off my fluid, it was about 1/2 way but that didn't help. If I remove the plug from the valve on the brake booster, there is no more noise and brakes work ok...at low speed. Since I only have manuals for the engine, I can't tell you if that means anything or not (probably doesn't).

Taking it in to have it looked at. Will report back.

[phantomknight321]

I hear this quite often as well, but i only have almost 16k miles. Let me know if you find anything out about it

[bryanakron40]

It almost sounds like the a valve fluttering in a vacuum hose, too. Kind of like a pcv valve or an evap solenoid.

[titan2782]

kobowm is correct in saying it's "normal" however, it's only been normal during first start when I flick the key to the on position all this time. I always thought it was the fuel pump (since all my other cars did this as well). Didn't realize it was the brakes.

I'll report what they tell me.

[titan2782]

Alright so the 1.4's have an extra vacuum pump to compensate. The service tech said I should bring it in. Have to wait for my PCV pipe to come in before I do it so it will be next week sometime.

[jblackburn]

I heard this noise once when I turned off the car and turned it back on.

Yeah, shouldn't be doing that all the time.

A lot of turbo VVT motors have these pumps to compensate for there being a total lack of vacuum at a cold, high idle with the timing off "normal" settings.


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[jblackburn]

HOWEVER I wonder if the pump is running just because you have a vacuum leak to make up for the lost vacuum to the brake booster? You said youre waiting on a PCV hose? Perhaps that's all it is and it will stop as soon as you fix that problem.

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[titan2782]

HOWEVER I wonder if the pump is running just because you have a vacuum leak to make up for the lost vacuum to the brake booster? You said youre waiting on a PCV hose? Perhaps that's all it is and it will stop as soon as you fix that problem.

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I'll check if that's the issue, but I doubt it. I've sealed it all up (maybe) and the pump is running even when the car is off which i know for a fact didn't happen because I regularly push my car out of the garage when cleaning it (I don't like to start it just to move it 15ft then turn it off).