The rear heater core is constructed from aluminum and plastic and is 
generally not repairable. You might try removing yours and taking it to a 
good radiator shop. They will pressure test it so that you can at least see 
where it is leaking. From what I've heard, once they start to leak, you 
might as well replace them. I just replaced this on my '87--cost $152 for a 
new core.

-Mark McCulley
>     
>     I just discovered that the core in my rear heat exchanger is leaking.  
>     
>     Of course, I don't recall whether it is repairable or if replacements are 
>     available for a reasonable price (sources if known) or if the whole unit 
>     has to be replaced.
>     
>     Anyone out there with the answer?
>     
>     Pat S.
>
>