A while back, Jim Davis neatly pointed out about changing trans fluid 
in automatics:
  "I did this a while back and it's just as you describe.  I did replaced 
the screen also.  My ATF had not been changed in a long while and I 
wanted to change as much of it as possible.  Since a significant amount 
of ATF remains in the trans during this procedure, I elected to change 
much of the ATF before the procedure.  What I did was use a plastic lube 
oil pump and snaked plastic tubing down the dipstick tube and pump out 1 
quart.  Then add 1 quart.  We'd drive it for another week or three and 
replace another quart.  I think I replaced about 6 quarts this way.  I 
recall calculating that I was able to replace about 95% of the old ATF 
after the screen & gasket change with new ATF.  If I recall correctly, a 
typical change only replaces about 60% of the ATF."
  Just going through old mail from a recent week's break and I nominate 
this as a candidate for everyone's "Best of Vanagon" folder as a keeper. 
 Excellent thinking.

	John