Dan if you would have searched the archives you would have found the 
following message which I sent to another List member who needed similar 
information.  The piston must be removed to install a seal kit which you must 
get from your VW dealer.  To remove the piston, remove the large circlip 
which is holding it in place.  There is a large heavy spring behind the 
piston and it should pop out.  If it does not it's because there is crud or 
corrosion around the perimeter of the piston.  You will need to clean this 
area with a small pick and tap on the piston until it comes out.  The rest of 
the story is below.

      >> I have been there and done this, so listen up.  The piston controls 
the second gear brake band.  The band is operated by two rods rods which 
contact the band in pockets at the bottom ends of the band.  When you 
released the piston the rods fell out of their respective pockets and that's 
why you cannot get the piston back in.  You must now remove the oil pan and 
then the valve assembly.  BE SURE TO KEEP EVERYTHING CLEAN DURING THESE 
OPERATIONS !  Once the valve assembly has been removed you will be able to 
see the two rods.  You will also be able to replace the ends of the rods in 
their respective pockets in the ends of the band.  Then you will be able to 
replace the piston.  The piston is very hard to push in as the spring tension 
on it is quite high.  I used a small hydraulic bottle jack to do this 
operation of pushing and holding the piston until I could install the 
circlip.  This also gives you some fee hands to look see if the rods are 
still in place.  You will notice that the rod on the opposite side of the 
band from the piston is controlled by an adjustment screw.  Do not touch this 
adjustment as it should be OK.  Bentley explains how to adjust this screw if 
you feel you must fool with it.  The explanation of the rods falling out of 
their pockets is not covered in Bentley as I suspect they did not presume 
that anyone would be changing the 0-rings on that piston assembly other than 
at a full transmission rebuild. Ha !  WRONG !  Good luck.<<

Cheers��

Frank Condelli
Almonte, Ontario, Canada
<A HREF="http://members.aol.com/BusFusion/bfhome.htm">BusFusion</A> a VW Camper camping event, Almonte, ON, May 30, 31, June 1, 2, 2002
'87 Westy & Lionel Trains
Member: <A HREF="http://www.vanagon.com/">Vanagon List</A>, <A HREF="http://www.bcn.net/~limbo/">LiMBO</A>, <A HREF="http://www.westfalia.qc.ca/CIW_English.asp">IWCCC</A> & Capital City VW Club 
Vanagon/Vanagon Westfalia Service in the Ottawa Valley
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<A HREF="http://members.aol.com/Fkc43/busindex.html">Frank Condelli & Associates</A> or http://frankcondelli.com