I read a post recently where someone mentioned tightening the roof mount A/C mounting bolts once a year. I had not heard of this, and while I've never had a leak, I decided to check mine today. The Dometic Penguin II manual states to torque them to 40-50in-lbs. It took about 8 turns on my rear A/C and 6 or so on the front A/C to get them to spec.
Just thought I'd throw this out there as a reminder to anyone that hasn't checked these in a while, or ever.
And be careful not to over-tighten or do so unevenly. The gaskets will permanently deform and you'll wind up having to replace them due to leaks.
Do NOT compress the gasket more than 50%.
The problem with quoting torque specs is that corrosion and wear due to vibration can significantly impact torque vs gasket compression.
When I did the gasket on my coach I found pieces of interior wall plywood used as shims while foam had been squirted in the space. So the 1 inch thick standard gaskets were too thick.
Any rig I've had that I felt like it was time to add torque to the air conditioning mounting bolts I replaced the gasket at that time - Doesn't take that much more effort if you're worried about a leak... But then there's the unexpected cleaning project that ensues! 🤣
And the inspection and likely reinforcement of the shrouds at the screw holes :D
Yup, stainless steel fender washers with a rubber gasket between the washer and shroud really spreads the load and extends shroud life.
I did like Wolfe said: SS washers and gaskets, also primed the plastic and painted all with spray cans to reduce UV deterioration, and the old yellowing was not pretty.
DUH. Me being an idiot savant injinear, I went a different route from the "included instructions" that came with my new AC seals.
I turned the adhesive side of the foam seal UP and put caulk down on the surface that contacts the coach roof....on both ACs.
Seems contrary to what everyone else does but---BUT!!!!!!!!!!!!! That was about seven years ago and haven't tightened any bolts or had any leaks whatsoever. Our coach sits out in the weather all summer and is in a covered building during the winter except when we went to South Texas for the winter, so my seal method must work.
I must admit, I forgot about tightening the bolts every year. DUH!!!!