I just replaced the core in my rear heater.  I did pull the rear seat.  After removing the vent cover I removed the entire assembly, 4 screws that attach the unit to the floor, one electrical connection and the coolant hoses.  The manifold where the coolant hoses connect and the core are all one piece (except for the valve which can be removed later) and is removed with two screws going into the case.  The whole core assembly should slide right out of the case. 

good luck

--Joe
87' Syncro 
  ----- Original Message ----- 
  From: Randy Charrette 
  To: vanagon@GERRY.VANAGON.COM 
  Sent: Tuesday, December 04, 2001 18:36
  Subject: Rear heater core replacement?

  Well the heater core is leaking in the rear. I have removed the cover and see 2 clips holding the front vent cover on. Then there is a plastic case with the heater core and blower motor inside. How is this case supposed to open. I expected to see screws going in the sides, but there were not. I don't want to break anything! Detailed directions appreciated!

  Randy Charrette
  87' Syncro weekender

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