Hello,

My rear heater is producing the unmistakable strong smell of coolant if I
run it. I've been keeping the valve closed but I'd like to use the heater as
it's a little bit cold this time of year without it. My van's a Westy so I
have easy access to the heater. I removed the wood box surround and don't
see any evidence of leakage anywhere. Is this a sign that it's definitely
the core that is the source of the leak?

I'd like to fix this soon and I want to make sure I order the parts I need.
I'm not sure how to diagnose the leak beyond the visual inspection I've done
so far. I'd rather not remove the core and open the cooling system until I
have the replacement part(s) here. Is the best thing to replace the core and
valve just on general principle?

Lastly, what's the proper R&R procedure so I don't have to bleed the cooling
system? Clamp the input and output hoses? Anything else?

I've searched the archive but it's kinda short on specifics for this topic.

Thanks in advance & happy holidays,
-Roger