Engine Cooling problem
1996 Alfa Romeo 155 s 4 cyl Front Wheel Drive Manual 235000 miles

Hello,

Could overfilling the coolant expansion tank over the mark level, causes leakage to the connecting pipes?

Recently, I added water in the coolant expansion tank.

A couple days later I could see green stains on the garage floor below the engine. It near the engine block near the oil filter.

Could overfilling cause leaks to pipe due to iincrease pressure?

I thought overfilling will just cause the water to evaporate though the cap of the coolant expansion tank.

Thanks