St. Muir (i.e. John Muir) has a very clear procedure
on this in his HOW TO KEEP YOUR VOLKSWAGEN ALIVE: A
MANUAL OF STEP BY STEP PROCEDURES FOR THE COMPLEAT IDIOT.

I know it's a clear procedure, because I've tried it and
it works.  If you don't have/have access to the book I'll
be glad to photocopy the pages & mail them along...  I can't
scan copy, so it has to be snail-mail, of course.

Mike Wright
Ackworth, Iowa
68 Camper; 79 Bus
wright@storm.simpson.edu