Because Electric Vehicles do not have an internal combustion engine there is no traditional vacuum source to supply the brake booster, so a vacuum pump and vacuum flask is needed. In fact it is mandatory for registration of the vehicle.
I have a MES-DEA Type 70/6E vacuum pump which is described in an earlier post and will not elaborate on that here; instead I will focus on the vacuum flask.
The reason to do that now … my vacuum flask failed.
The vacuum flask in MR02EV is pretty simple:
I have seen several different approaches to building vacuum flasks for modified vehicles (like EVs and Hot Rods) including 4x4 OEM parts, recycled fire extinguishers, and different configurations of PVC pipe. In my case PVC pipe was easy and available.
The PVC vacuum flask has reliable for several years and only failed because I modified to fit a different location in the car and used old PVC glue, which would not hold an air-tight seal. The failure was my poor construction efforts, not the design.
We found the air leak by pressurizing the brake vacuum lines and flask using a 12v air pump, then placed soapy water on all connections and joints. And just to prove the point (when the flask itself was suspected) we put the flask in a bucket of water, and there it was.
The problem was solved with a new end cap and a liberal amount of fresh PVC glue.
I have a Degree in Electrical Engineering from the University of Technology Sydney and am employed in Broadcast Television Industry. My hobby is the (continuing) modification of MR02EV. I am also the National Treasurer of the Australian Electric Vehicle Association.