Brakes making a small popping noise

I've only had my FFE for a few weeks now. I've noted that the breaks make a small popping noise when you first press down - almost as if there is an air bubble in there? This happens since it is only when you first press down, it doesn't happen midway through the braking process. It doesn't happen each time, but enough to make me wonder about it. Is this something that is normal to the regenerative breaks or do I need to take it in?

I've never noticed anything like that. The only odd behavior that I've seen from time to time is:
1) If coming to a slow and gradual stop, there is a moment when the regenerative braking will stop and apply only the traditional brakes...this would be the transition from 100% regen to 100% friction. If you are stopping with some percentage of friction, you typically will not feel the transition.
2) Sometimes, when I leave my housing tract, I will feel a very short surge in the brakes. It is at the bottom of a hill and usually I will be braking a little harder. It almost seems like it could be #1 above, but in a different scenario. It doesn't happen that often. It could even be a pothole or something that is near the stop sign.

Anyway, neither scenario seems to match your issue. If it doesn't seem like a safety issue, I'd wait till you figure out how to make it happen so you can demonstrate it to the dealer; otherwise, they won't figure it out and return it to you with no defect found (NDF).

I hear a noise when pressing the brakes down initially. I wouldn't call it a popping sound, though. To me it sounds more like a piezo device. Its very hard to describe the sound. I've never thought that the sound was some sort of problem though, just another noise unique to the FFE. Almost 15,000 miles on it now and the car still performs (and sounds) the same as it did when I picked it up.

chiapet6 said:

I've only had my FFE for a few weeks now. I've noted that the breaks make a small popping noise when you first press down - almost as if there is an air bubble in there? This happens since it is only when you first press down, it doesn't happen midway through the braking process. It doesn't happen each time, but enough to make me wonder about it. Is this something that is normal to the regenerative breaks or do I need to take it in?

Click to expand...

If you've been on the accelerator and then transition to the brakes you might hear a noise as the electric motor starts generating electricity instead of consuming it. Is this when it happens?

What are your brake scores like? Do you get a 100% brake score when it happens?

jmueller065 - I'm not sure about the OP, but I think that you're describing the vacuum pump [there's no venturi effect in an electric motor] for the brake's vacuum servo. The accumulator needs to get 'topped-off' occasionally and the car fires off the pump when it thinks you might be wanting to use the brakes soon.

Nope not the vacuum pump. The VP on mine sounds just like an aquarium air pump.

I'm talking about the small noise you hear when switching from accelerating to braking. I've also come up with another possibility for its source: The gears lashing. When the engine switches from drive to braking the torque reverses which would cause all of the gears to switch the load bearing faces to the opposite side. If there is any play in the gears there will be some noise as the teeth separate and then meet again on the opposite faces.

The FFE only has 3 or 4 gears and a differential, look at the pictures here for a cut-away:
http://jamiegeek.myevblog.com/2013/09/09/motoring/

jmueller065 said:

I'm talking about the small noise you hear when switching from accelerating to braking. I've also come up with another possibility for its source: The gears lashing. When the engine switches from drive to braking the torque reverses which would cause all of the gears to switch the load bearing faces to the opposite side. If there is any play in the gears there will be some noise as the teeth separate and then meet again on the opposite faces.

The FFE only has 3 or 4 gears and a differential, look at the pictures here for a cut-away:
http://jamiegeek.myevblog.com/2013/09/09/motoring/

Click to expand...

This is the noise I was referring to. Thanks for explaining it better than I did.

I usually get 100% regan when I brake. It is right when you first touch the brake, it is just this little "pop". Couldn't get to the dealer over the weekend, so so will try to this Saturday. There isn't a catch or lurch when it happens.

Only sound I hear then is the brake light switch.