I have a 2005 Ford focus. I haven’t even had it 8,000 miles. THREE times it has overheated, and I’ve had to replace over a gallon of coolant. The first two times, the cause was a leaky ‘vacuum’ cap. The third time it was a different cap that was leaking. This radiator has two (that I know of) unused ports on it. A 3/8" one on the top left, and a 5/8" one on the bottom left. They are capped off with little rubber vacuum caps, which are quite simple to replace. But, these things don’t last long before they start to weather and crack and leak. I just replaced them after 2,000 miles (before they started to leak), and they’re already cracked. But oddly, only on the OUTSIDE. Inside they’re still smooth and unbroken.
I’ve asked for advice at auto parts stores, mechanics, and even at a radiator shop. They all say they’ve never heard anything like this before?!
I just got some silicone vacuum caps which are specifically rated for high temps, but they’re so thin I’m not sure I wanna install them.
Anyone ever hear of a problem like this?