Coolant on the inner fender or stains below the radiator cap usually mean the overflow tank isn’t doing its job. On many classic Chevy Camaros, Chevelles, and El Caminos, original tanks crack, discolor, or disappear altogether after years of repairs and rebuilds. Without a functioning recovery system, coolant expands, vents, and never fully returns to the radiator once the engine cools down.

Replacing the overflow tank helps maintain proper coolant levels and keeps the system from pulling air back in during cooldown. It’s a small component that plays a big role in stabilizing operating temperature over time. Many restorations address overflow tanks while correcting broader cooling concerns tied to fans and fan shrouds or when replacing aging radiators, since consistent coolant management depends on the entire system working together.