I know this has probably been covered somewhere already, but just in case, I though I'd post this.
We're currently living in our RV in Palm Harbor Fl, while waiting for houses to close. Our Pace Arrow is a 2005. I've had to replace two skylights in the 5yrs we've owned it, and used a combination of Dicor sealant/caulk and Eternabond tape.
A few weeks ago we got hit with some VERY heavy rainfall, lasted on and off for about 6hrs. I discovered a small leak in the kitchen, near a fan.
The next day, while dry and sunny, I climbed up on top for a look-see.
I examined all of the "pass-throughs" on the roof, and found that in many places, the older Eternabond tape had some very small cracks in it. Maybe the name should be "FairlyLongbond" instead of "Eterna"?
Anyway, I headed for Home Depot and grabbed two cans of white FlexSeal, and gave every seam on the roof two coats, about 4-5hrs apart.
We've had two heavy rainstorms since, and not a drop or drip inside the coach.
I'll keep checking on it every month or so, but so far, it seems that FlexSeal might get added to my maintenance schedule. A lot cheaper and a lot easier to apply than the traditional sealants.