Can a car break down from a coolant leak? Bf said he has a coolant leak that it was "pouring out". Saw nothing when i looked after we drove it back to his house, he said it was because it was out of coolant now. He is worried it's going to break down on him. When I googled the problem, it said that there should be a low coolant light that comes on. But there isn't, do all cars have that? It isn't over heating, at least not yet, which is surprising because it's in the 90's and we drove it for at least two hours today. Honestly (not to be mean but ) I'm wondering if he has even the slightest clue what he's talking about. Told him he could keep a gallon of water in his car just in case it starts to overheat but he said "I can't drive it like this or it could break down". Any replies would be greatly appreciated.