No corrosion at all as I've been really good with coolant.
I lightly sanded any old residue off and it was very clean.

I guess it's always a possibility the aluminum pump face has warped slightly over time and in this heat. I'll give the sealant a try and if no luck, I'll just have to replace it.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k