Why does the radiator cap open and close?
Why does the radiator cap open and close?
One of the things that has not been mentioned is that the radiator cap serves a dual function. It maintains a pressure when the radiator is hot, but also has a secondary valve that is blocked when the radiator is pressurizes, but opens when the radiator pulls vacuum to let the coolant from the reservoir go back to the radiator.
Why is my radiator overflowing with coolant?
No one’s mentioned the simplest thing yet. If the system is overfilled, it will overflow. As it heats up, the coolant expands and that is why you don’t fill up the overflow bottle all of the way. (If you are pouring fluid directly into the radiator, you do fill it up completely.) Your radiator cap may be bad.
How can I tell if my car radiator is failing?
The second way a radiator can fail is to become plugged internally. To check for this condition, remove the radiator cap when the engine is cold look inside using a flashlight. You may need to drain some of the coolant out to see the ends of the radiator core tubes.
When does the coolant go back into the radiator?
It maintains a pressure when the radiator is hot, but also has a secondary valve that is blocked when the radiator is pressurizes, but opens when the radiator pulls vacuum to let the coolant from the reservoir go back to the radiator. If the coolant is dirty, the secondary valve can get plugged.
What happens when you change the cap on a radiator?
If so, then replace the cap. Coolant goes into the reservoir tank as it expands. The radiator cap is released by the pressure and the coolant is sent toward the overflow tank. If you have a bad radiator cap, the coolant will get released too quickly and cause the reservoir to boil over.
What should the radiator cap pressure be on a Ford Mustang?
A 16 psi cap system will boil at 266F. Your car isn’t going to be running at anything close to either of those temperatures. With no radiator pressure, coolant will boil at 224F which is too close to what the engine might see which is why radiator caps pressurize the system.
What does it mean when your radiator hose collapses?
Your radiator hose collapses: If you open your hood and notice that your radiator hose has collapsed from internal suction, this can be a symptom of a bad radiator cap. Your cap is likely not letting coolant from the expansion tank be drawn back into the cooling system as it cools down.
What happens when coolant comes out of the radiator?
Your engine boils over: The normal flow of coolant through the radiator cap changes quickly if the liquid begins to boil. Boiling coolant becomes steam. Massive amounts of pressure must be released quickly through the radiator cap. This pressure will be released into the overflow tank, and steam can usually be seen escaping from under the hood.
