Sunday, March 09, 2008

Vacuum Brakes Revisted

March 5, 2008

The weather is finally improving and it's actually getting up to 50 deg. (f) during the day. We still have snow laying around in the shaded areas, but it's about gone. Even the fields are starting to green up.

I'm starting to drive the car again, so I decided I better upgrade and reactivate the power brake system. It's not too bad driving with no brake booster, but I think it would be hard to lock up a wheel in an emergency stop. Also, since I'm letting others drive it occasionally, it's sort of a safety issue.

What I did was replace the vacuum switch (the switch that starts and stops the vacuum pump) with a much better switch from EV Parts. It's adjustable. Next, at the suggestion of several members on the EVDL (Electric Vehicle Discussion List) I put a "surge protector" in series with the vacuum pump motor. (The protector is a ten ohm thermistor.) What the thermistor does is cause the vacuum pump to do a "soft start," which is much more "gentlemanly like."

The system is working good and is now virtually unobtrusive ... and it hold vacuum quite well.