Of all the threads about replacing the heater core in the Foxes most mention how important it is to remove all of the "dumb gum" (black gooey sealant in the bottom of the heater core box) to avoid premature failure of the new core. But hardly any mention what they used in place of it. I've seen one guy who used Dow Corning 3140 RTV sealant (good luck finding it), a couple who used RTV sealant, and the rest don't say.
So what to use? Is regular black RTV sealant OK to use on the bottom of the new heater core (in between the core and the box)? Something else?
So what to use? Is regular black RTV sealant OK to use on the bottom of the new heater core (in between the core and the box)? Something else?