I would recommend replacing the rotor on both sides and also replacing your pads.  This way you have even braking on both sides and a fresh start for your front brakes.  Changing these items is actually quite simple especially for the syncro as the rotor is removable without taking off the hub (all 2wd Vanagons require this and fooling with wheel bearings, where you do not have to worry about this.)
I have new, VW brake pad sets for $25 (does both sides) and front syncro rotors for $50 each (German).  Give me a call or order through the web store.

Thanks,
Ken Wilford
John 3:16
www.vanagain.com
Phone: (856)-765-1583
Fax: (856)-327-2242