* Faulty radiator cap: This is the most common culprit. A bad cap won't release pressure properly, leading to increased pressure in the system.
* Head gasket leak: This is a more serious problem. A head gasket leak can allow combustion gases to enter the cooling system, increasing pressure.
* Cooling system blockage: A blockage somewhere in the system (radiator, hoses, water pump) can restrict coolant flow and increase pressure.
* Water pump failure: A failing water pump can't circulate coolant effectively, leading to pressure buildup.
* Thermostat issues: A stuck closed thermostat will prevent coolant from circulating properly.
A hard hose is a warning sign and should be investigated immediately. Ignoring it could lead to more serious damage, including engine overheating and potential catastrophic engine failure. Have a mechanic inspect your cooling system to diagnose the underlying problem.
