I may have been able to do it without the socket(I didn't try), but I have a set of these 18mm 3/8&#34 Drive Flare Nut Socket by: Koken - UKtools Limited - Hand Tools : (I got them to work on hydraulics) and it made the job easier

 

I was able to change out the sensor by using a standard socket with a angled knuckle adaptor. The rave however recommends taking the alternator out to allow access to the sensor.

Changing out the sensor has seamed to correct the intermittent issue.