Question about heater core install

[saxart]

The instructions that came with my heater assembly gasket kit from "Classic Parts" says to put the clay-like "rope gasket" calking cord between the new heater core and where it lays against the inside of the heater box. (Where it says 32" calking cord here.)



This doesn't make sense to me. Seems like it would just be a gooey mess when that heater core gets hot. Does anyone have thoughts here? I already installed the heater core (without the cord) so I'm wondering if it's really worth pulling apart to get it in there.

Got thoughts?

[Toms67]

Mine came with the foam gaskets. Must be the calk is what they used originally? I don't know what it will hurt to leave it out?

[Freddo]

I installed my heater core about two years ago. It did not come with the gasket and when the old one came out there was no gasket. I reinstalled it with no gasket and it has worked just fine.

[saxart]

Thanks guys, this is exactly the info I was looking for. I'm going to leave it as is.

[Jrainman]

The butyl tape , calk , gasket : is the proper and best way to seal any type of plenium / duct conection it will not dry out overtime like other materials and will act as a constant seal for many years . it is a industry standard way to seal things that have air moving through them. and No it will not melt .

[Andy4639]

I just used the puddy stuff around it and it sealed of good. I super glued the fan gasket on before installing it. I tried 2 times with out the glue and it feel off both times. The 3 time it didn't!