I must also add that I've sprayed PB Blaster on it, but after the fact and I was using a 6 point socket with a breaker bar. I was using an impact motion to try to make it break, but they still rounded. It's also odd that on the ones that did break had pressurized liquid come bubbling up out of it. I suspect this is the reason the cap bolts were so tight making them round off. Is there a way to relieve this pressure, or do I need to get an extractor socket set?