[Raymond Ramesar]

1) Has any of you owned a Smart 451 ED new from the dealer?
I find it hard to believe that people heard that noise while test driving a new car at the dealership. I can imagine the conversation, "Wow, driving an electric vehicle is so quiet BRRRRRRRRRRRRRRRRRR...".

2) If you did, do you remember hearing that "brake booster pump" noise?

I'm reading the service manual and came across page 63:

Note
The number of operating hours of the vacuum pump must be determined using DAS at the following intervals:
• Up to 4 years/125,000 km: every 2 years
• After 4 years/125,000 km: annually

The brake booster vacuum pump must be replaced after 1200 operating hours. If replacement is required, this is indicated by the drivetrain control unit.

Is that why we're getting the noise as "normal" on all our used Smart 451 EDs?

3) Because after 1200 hours of operating it needs to be replaced or it makes this noise and eventually fails/malfunctions?

 

[Yinzer]

1) Has any of you owned a Smart 451 ED new from the dealer?
I find it hard to believe that people heard that noise while test driving a new car at the dealership. I can imagine the conversation, "Wow, driving an electric vehicle is so quiet BRRRRRRRRRRRRRRRRRR...".

2) If you did, do you remember hearing that "brake booster pump" noise?

I'm reading the service manual and came across page 63:

Note
The number of operating hours of the vacuum pump must be determined using DAS at the following intervals:
• Up to 4 years/125,000 km: every 2 years
• After 4 years/125,000 km: annually

The brake booster vacuum pump must be replaced after 1200 operating hours. If replacement is required, this is indicated by the drivetrain control unit.

Is that why we're getting the noise as "normal" on all our used Smart 451 EDs?

3) Because after 1200 hours of operating it needs to be replaced or it makes this noise and eventually fails/malfunctions?

No, that noise when you first turn it on and every few brake applications is the normal pump operaiton. My ED made that noise since it was new. Note that the 1200 hours is the pump operating hours, not the car operating hours. After 1200 hours on the pump (you can check the pump hours with the battery pack diagnostic unit that that hte Sokoloff's sell) you will get a service message - but the car is still operable.

 

[Yinzer]

No, that noise when you first turn it on and every few brake applications is the normal pump operaiton. My ED made that noise since it was new. Note that the 1200 hours is the pump operating hours, not the car operating hours. After 1200 hours on the pump (you can check the pump hours with the battery pack diagnostic unit that that hte Sokoloff's sell) you will get a service message - but the car is still operable.

Also, I just checked a scan from a little less than a year ago, and in a 5.3 years of use and 39K miles of driving, the total hours on the brake vacuum pump was 67.625 hours. So at this rate, the pump will "hours out" in late 2114!

And have you used the AC yet? The startup of the AC compressor sounds like a airliner engine starting up.