intrepion
Posts: 42
Joined: Thu Oct 14, 2010 9:19 am
Delivery Date: 05 Apr 2011
Leaf Number: 0649
Location: Portland, OR

Anyone notice a buzzing noise while braking?

Sun Jun 05, 2011 6:49 pm

I tend to notice it when I'm stopped at a red light and there's this low pitched buzzing sound after several seconds of hitting the brakes. It lasts about half a second, then repeats every several seconds. It doesn't stop immediately when I start going again, but it does stop after accelerating for several seconds.

Anyone else having this happen?
Blue Ocean SL-e
Portland, OR
Delivered April 5, 2011

TurboFroggy
Posts: 107
Joined: Sat Jan 01, 2011 10:41 pm
Delivery Date: 21 Jun 2011
Leaf Number: 2398
Location: Everett, WA
Contact: Website

Re: Anyone notice a buzzing noise while braking?

Sun Jun 05, 2011 9:01 pm

More than likely this is the vacuum pump for the breaks. You can test this by going to a quiet area, like in your garage etc with the windows down. Then with the car on, pump the breaks with it in park, you will hear the buzz when the vacuum pump comes on then it will turn off when it gets enough vacuum built back up.
My Ranger does the exact same thing, but it is very loud compared to the Leaf's pump. There are a few videos of the Ford Focus EV that you can hear the same loud vacuum pump that is in my Ranger in the Focus.
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User avatar
TomT
Posts: 10645
Joined: Sun Aug 08, 2010 12:09 pm
Delivery Date: 01 Mar 2011
Leaf Number: 000360
Location: California, now Georgia
Contact: Website

Re: Anyone notice a buzzing noise while braking?

Sun Jun 05, 2011 10:03 pm

Just to clarify, the Leaf does not use a vacuum booster brake system, it uses an electric motor built in to the brake cylinder assembly. There is a super capacity in the back near the charger that provides backup power in case of a total electrical failure. This is all documented in the service manual.

TurboFroggy wrote:More than likely this is the vacuum pump for the breaks. You can test this by going to a quiet area, like in your garage etc with the windows down. Then with the car on, pump the breaks with it in park, you will hear the buzz when the vacuum pump comes on then it will turn off when it gets enough vacuum built back up.
My Ranger does the exact same thing, but it is very loud compared to the Leaf's pump. There are a few videos of the Ford Focus EV that you can hear the same loud vacuum pump that is in my Ranger in the Focus.
Leaf SL 2011 to 2016, Volt Premier 2016 to 2019, and now:
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