Have a question. I have noticed some radiator leakage but it’s not from under the radiator. It comes from the area of the overflow. I was just wondering if maybe I need a new radiator cap cause my car actually doesn’t overheat. I have noticed that it only does it if I drive for a longer time than 1/2 hour.
I can even drive with the air conditioning on and it doesn’t overheat in that amount of time.
Make, model, year, miles? Does it have a pressurized overflow tank? It wouldn’t hurt to try a new radiator cap, the old one might be holding pressure. " I have noticed that it only does it if I drive for a longer time than 1/2 hour." Does this refer to overheating or a coolant leak?
Is the radiator cap on your overflow container or on the radiator, could be a bad overflow hose or jug even, cn you be a little more specific? Or even post a pic!
How much coolant are you losing when this happens? Have you checked the coolant level in the radiator itself (when cold)?
One caution first. Does your car ever overheat? If it does, even infrequently, you need someone experienced to at least find out why. Otherwise you could be looking at a repair way more expensive than a new radiator cap in the future.
The source of the leak could be from the radiator and you just can’t see where, or possibly the plastic tube that goes from the top of the radiator to the overflow bottle. Replacing the radiator cap is something you can do which is inexpensive and at least has a chance of working. I expect though that your radiator is leaking where the top part which is plastic meets up with the core, which is metal. Especially if your car is more than about 12 years old. Radiators these days are not as robust as they used to be, and are more or less considered a normal replacement item. The advantage is that they are also weigh a good deal less than before, so you get better mpg.
Leakage from the overflow tank could be a symptom of a leaking head gasket, especially if the engine eventually overheats. Exhaust gases leak past the head gasket into the cooling system, pressurizing the coolant and expelling it from the overflow tank. The hot exhaust gases also cause the coolant to overheat.
You said the engine is not overheating now, but if it does start to overheat, a head gasket leak is a possible culprit. But first try a new radiator cap like George said above.