Last week on the interstate, the coolant lines that run to the heater core broke at both plastic fittings and blew out most of the coolant. Was on my way to the airport so had a shop replace the hoses while I was away for a week. This morning I drive it for a while and find out the passenger side top radiator hose blew off and lost a bunch of coolant again. I'm thinking either the pinch-type hose clamp is weak, they didn't secure it correctly, or there's too much pressure building up. It did pass a combustion leak test. Have you guys seen this before?