AC Unit Question

muz123 · 06-18-2011, 07:57 PM

I just got a leak in our '05 3023 after a hard rain. After going on the roof to investigate I noticed that the hard plastic "shroud" that the AC Unit is mounted on has caulking all the way around it and about a 4-inch section was split along the edge probably due to flexing of the plastic. Also looked on the forum and noticed that the mounting screws may require tightening.

I couldn't help but wonder if the caulking around the edge of the plastic that the AC Unit is mounted is required. Could that be the cause of the leak? Already re-caulked the edge... Any advice?

**commodor47** · 06-19-2011, 04:41 AM

We had a similar leak and discovered the "mount gasket" had deteriorated and needed to be replaced; tightening the mounting screws you refer to did not stop the leak. I opted to have the mount gasket replaced (two years ago) at our TM dealer . . . no more leak . . .

Dick

muz123 · 06-19-2011, 06:00 AM

Dick

Thanks, I'll take a look at it. I noticed that the AC Unit Gasket, that usually comes in contact with the roof, does not do that in my camper. Instead, there is much larger opening and the gasket comes in contact with a hard plastic that the AC Unit mounts on top of. Is this normal for all TMs? Should I caulk around the outside and inside the TM of this plastic piece?

**commodor47** · 06-19-2011, 06:54 AM

The sketch came with the documentation from the TM factory. As part of the documentation they included all installation and instruction manuals for the appliances/units installed in our TM. The attached thumbnail is a fairly large photo. Try opening the thumbnail, left click on the image, left click again on the image which should bring up the '+' cursor icon and left click on the image one more time. That should bring up the full size copy (8.5 x 11) and allow you to use the print function under the 'File' button of your browser. Let me know if that works . . . if not I can send you a larger copy via email.

Dick

muz123 · 06-19-2011, 06:57 AM

Found the picture in my old documentation! I noticed that the AC Unit Gasket, that usually comes in contact with the roof, does not do that in my camper. Instead, there is much larger opening and the gasket comes in contact with a hard plastic that the AC Unit mounts on top of. Is this normal for all TMs? Should I caulk around the outside and inside the TM of this plastic piece?

**commodor47** · 06-19-2011, 07:12 AM

I am trying to picture the structure you describe . . . It might be better to check the mounting bolt gasket indicating tab for correct positioning before attempting replacement of the mount gasket. My mount gasket and mounting bolts is visible from inside the TM by removing the ceiling grille, air filters, ceiling assembly, and duct collar (see attached thumbnail).

Dick

**commodor47** · 06-19-2011, 07:18 AM

Quote:

Originally Posted by muz123

Found the picture in my old documentation! I noticed that the AC Unit Gasket, that usually comes in contact with the roof, does not do that in my camper. Instead, there is much larger opening and the gasket comes in contact with a hard plastic that the AC Unit mounts on top of. Is this normal for all TMs? Should I caulk around the outside and inside the TM of this plastic piece?

In many installations a plastic spacer is used between the unit and the roof. This allows for level installation of the unit. Is what you describe a tapered plastic shim? (thicker towards the rear of the shell?).

Dick

ELM-JLM · 06-19-2011, 08:58 AM

Quote:

Originally Posted by muz123

I just got a leak in our '05 3023 after a hard rain. After going on the roof to investigate I noticed that the hard plastic "shroud" that the AC Unit is mounted on has caulking all the way around it and about a 4-inch section was split along the edge probably due to flexing of the plastic. Also looked on the forum and noticed that the mounting screws may require tightening.

I couldn't help but wonder if the caulking around the edge of the plastic that the AC Unit is mounted is required. Could that be the cause of the leak? Already re-caulked the edge... Any advice?

I am attaching a few pic's I took at the factory in April! I hope they give some insight!

muz123 · 06-19-2011, 03:20 PM

Added pictures to show where someone had made a "dent" in the inside roof (and where water had leaked). I sealed the outside of the plastic piece that the AC sits on (see picture) (a little messy). I plan to seal the inside too to ensure no water gets in. Should I use eterna -bond on the outside too?
-Dave

**Bill** · 06-20-2011, 07:18 AM

Once the outside is properly sealed, I'm not sure that I would seal the inside. After all, if the outside is sealed, no water should get in, so sealing the inside is not needed. And if the outside is not properly sealed, then sealing the inside will just trap water and hide the problem - which can have much bigger consequences.

Just my thought.

Bill