GM-GMC: leaking heater core, chevy 454ss, heater cores

Question
I have a 1992 Chevy 454SS truck that leaks fluid (coolant) into the passenger compartment.  I have now replaced about 7 heater cores and switched the actual radiator to an alumunum one as recommended by Chevy.  The last heater core was replaced in November 2003 and I just replaced one today.  This does stop the leaking into the cab but obviously something else must be going on. Heater cores should last longer than 1 year.  What is causing the heater core to wear out so fast? What can I do to fix the problem for good? Thank you.  Wayne

Answer
The most common faults are:

1. the WRONG type of anti-freeze and or your mixing different brands. Use ONLY what the manufacturer recommends.

2. your building up excessive coolant system pressure. Either TEST or replace the radiator cap with the CORRECT one as recommended by the manufacturer.


thomas