Our van is nearly ready to hit the road after a year's work to rebuild the engine.  I bought this one with a blown engine.  The rear heater os leaking, and I am wondering if the valve tends to leak, the O ring, the core?  If there is a most common failure I will do that or do generally rebuild the whole unit?  The valve defiantly is leaking.
Thanks,
Finn Runyon
87 Westy Roo
89 Westy Pooh
12 GTI Autobahn