With a radiator cap pressure tester. The tool usually comes along with a cooling system pressure test kit.
Radiator caps are pressure relief valves. They are rated at "pounds per square inch" and are designed to release some pressure from the radiator if it gets too high. If an engine overheats it can boil the coolant and this will cause the radiator cap to let out steam. Radiator caps DO lose their ability to regulate pressure and can release too soon. If the engine has not overheated, have the radiator cap tested and replaced as necessary.
You should have pressure in the cooling system. The radiator cap is marked as to how much pressure it is designed to hold, usually 15 to 17 lbs.
The PSI (Pounds per Square Inch) rating is what pressure the radiator cap is designed to hold up to but not exceed in the cooling system.
Water under pressure has a higher boiling point, if the water is already hot enough to boil it will suddenly erupt when the cap is removed and pressure relieved.
It's a pressurized system. When it exceeds cap release pressure, it comes out.
Defective radiator cap? Leak in system (Pressure test)? Head gasket?
You attach a pressure test kit to where the radiator cap goes, and pressurize the system. If it holds pressure, it's good.
the radiator pressure cap was invented by Albert Einstein
No , the " radiator " cap / pressure cap is the thread on cap on the engine coolant reservoir
The thread on cap on the engine coolant reservoir is the pressure cap / radiator cap
The thread on cap on your engine coolant reservoir is your pressure cap / radiator cap
The thread on cap on your engine coolant reservoir is your pressure cap / radiator cap
No , the thread on cap on the engine coolant reservoir is the pressure cap / radiator cap
The thread on cap on your engine coolant reservoir is the pressure cap / radiator cap
The thread on cap on your engine coolant reservoir is the pressure cap / radiator cap
The thread on cap on your engine coolant reservoir is the pressure cap ( radiator cap )
The thread on cap on the engine coolant reservoir is the pressure cap ( radiator cap )