WRONG !  They are indeed square rings.  I have the OEM ones here from VW and they are indeed O-rings with a square profile.  O-ring, rear heater core to valve, 861 819 297                                                                                                

On 2012-11-01, at 8:18 PM, Automatic digest processor <LISTSERV@GERRY.VANAGON.COM> wrote:

> Many VW components use normal round-shaped o-rings.  They start out
> round in cross-section, but get compressed and flattened into the
> squared groove upon assembly.  When they've been in service for many
> years, they harden and take a set into this square shape, and it's only
> a matter of time before they start leaking, as they no longer are the
> same size or shape.  You may be able to get it to seal up again by
> adding some sealant and re-assembling the parts, but it really just
> needs a new o-ring.

Cheers,    

Frank Condelli
Almonte, Ontario, Canada
'87 VW Westy, '00 Kawasaki 250 Sherpa, "98 Ducati 750 Monster & Lionel Trains (Collection for sale)
Frank Condelli & Associates - Vanagon/Vanagon Westfalia Service in the Ottawa Valley
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