Those Prestone flush tees always crack as they age. I used one when I was young and dumb on my 1969 Dodge Dart. You can replace it with a 5/8" copper tube. I don't know if that hose is still available. If you fab your own like I did, note that the side at the engine is much larger OD. I used 2 sizes of silicone hose.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans