You need to get a used heater core, one that has some experience.
If you burst it you definately know something is dead wrong.

On Fri, 13 Jul 2001 19:13:10 -0400 Paul Cavanaugh
<phonyexpress@IWAYNET.NET> writes:
> Hi Leon,
>
> I have lost two trans coolers, so I will look into the
> "supercooler",
> maybe check Rocky Mountain motorworks.
>
> My mechanic tested the OLD cap and found it failed on the weak side
> -
> wasn't holding any pressure.
>
> He has no idea what has caused the 4 heater cores and 2 transmission
> coolers to go.
>
> Mechanic's assistant says BMW & VW are the only ones he know of that
> mount the coolers on the transmission; everyone else runs hoses up
> to
> a cooler by the radiator. Also says VW is the only ones he's ever
> seen go bad.
>
> Any other ideas? I have an appointment next weak at another repair
> shop...
>
> Thanks,
> Paul
>
> >Could you be cpecific about what is actualy bursting?
> >I think i mentioned before there is more reliable aftermarket trans
> >cooler(called Supercooler) that can solve this problem.
> >Leon
> >85 Subwagen Westy
> >
> >Paul Cavanaugh wrote:
> >
> >>  Well, the mystery continues...
> >>
> >>  My mechanic tested the coolant (while the engine was both hot
> and
> >>  cold) for traces of combustion leakage (hydrocarbons in the
> cooling
> >>  system) and found nothing.
> >>
> >>  He also found no excessive pressure in the oooling system (I
> replaced
> >>  the expansion tank pressure cap 2 weeks ago, just to be safe).
> >>
> >>  No explanation for 4 rear heater cores and 2 differential
> coolers
> >>  bursting in one year!
> >>
> >>  He is suggesting it could this be an intermittent problem??? I
> don't
> >>  want to lose another transmission!
> >>
> >>  Any ideas from my Vanagon.com friends would be welcome.
> >>
> >>  Thanks,
> >>  Paul

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