How often do you replace your A/C Gasket?

[benjburton]

About 4 years ago I finally figured out why my camper was leaking. It was a worn A/C gasket. I'm the second owner, and my camper was 7 years old at the time of replacement. I'm assuming that was the first time it was replaced. Now, 4 years later, it's leaking again. I've tightened the bolts down a couple of times now, beginning about 6 months ago, which fixed the leaks. However, now no matter how tight, it leaks, so I think it's time to replace the gasket again. Just seems that a 4 year interval seems a little too frequent. Is this normal? I always erred on the side of not too tight as not to compress the gasket too much, hopefully giving it a longer life, then tighten when necessary if water leaked. Have you had to replace your gasket more than once, and about how long did it last?