Usualy anodised iron, a Spring, and neoprene.
When the cooling system is overheated, the coolant is at pressure. Removing the radiator cap will release the pressure, and allow the coolant to boil, probably splashing you with boiling-hot radiator fluid. Your arms and hands will certainly be burned, and there's a good chance that the boiling coolant will splash your face. You wouldn't like it if that happens.
1943
The purpose of a radiator is to transfer heat as quickly as possible. It is pretty much the opposite of an insulator.
thermostat stuck in the closed position, or blown head gasket, to check remove the raditor cap when the engine is cold and then start the engine if you see large bubbles coming out of the raditor the head gasket is bad
Steam radiator valves should always be fully open, or fully closed. Steam enters the radiator from the boiler, and fills the radiator. The air vent shuts, having sensed moisture inside the radiator. The steam then cools, condenses to water, and drains from the radiator. If you leave a valve partially open, then the steam enters easily, because of the pressure. But, the water has a difficult time draining, so the radiator can collect it, and steals it from the furnace, which needs it for resupply.
If you have a threaded cap on your coolant reservoir that is your " radiator cap "
No , the " radiator " cap / pressure cap is the thread on cap on the engine coolant reservoir
The radiator cap is on top of the radiator.
the radiator cap is on top of the radiator you idiots
A lot of vehicles don't have the radiator cap on the radiator , they use a thread on style cap on the engine coolant reservoir ( that is the pressure cap / radiator cap )
The radiator cap is located on top of the radiator.
The thread on cap on your engine coolant reservoir is your pressure cap / radiator cap
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
On a 2004 Ford Freestar : The thread on cap on the engine coolant reservoir is the pressure cap / radiator cap
where is the radiator cap on a 2002 tribute
Your radiator cap is made of metal and rubber. The metal and rubber are reacting to the rust in your radiator. Rust and oxidation in your radiator will deteriorate the cap at an accelerated rate. I suggest flushing the cooling system and replacing the coolant and cap. If it persists after that you might have a heat problem that is cooking the rubber right off the radiator cap. If this is the case you should check your thermostat and heating Coil.