Dometic A/C mounting bolts

[Doug2009FC]

Have been experiencing leaks from rain entering my 2009FC 27FB for a few years now. Snugging up the mounting bolts helped up until a month ago. Decided to replace compression gasket. Discovered only three mounting bolts are used to secure A/C and compress gasket even though there are five mounting bolt positions and five bolts that come with the Penquin unit. AS service dept. says three are all they use--along with copious RTV--according to installation agreement with Dometic. Am I the only three bolt guy out there? What do they do with the extra bolts? I can see how leaving out two bolts could shave 90 seconds from the installation process. Dometic only wants $19 for the bolts plus $15 shipping. How can a square gasket be properly compressed with three bolts?

[Belegedhel]

I just installed a Dometic last summer, and the installation kit only had three bolts in it. I too had my doubts about the 3 bolt set-up, but so far I have had no leaks, and every time I return from a trip, the AC is still on top the trailer.

good luck!

[drboyd]

If you mean "RTV Silicone," please don't use it on aluminum. It will cause leaks and it's a biscuit to remove once you do put it on. You want a urethane sealant - search these forums for some excellent advice on the urethanes.

[63air]

The latest issue of Trailer Life has a great tech article on just this subject. I think you would find it quite helpful.