DIY replacing A/C pan with Cups

[bbradb]

As I'm finishing up replacement of A/C pan with cups on Penquin I, I have a question that I haven't seen answered here. I'm using 2 gaskets as advised by Dometic and others, however I haven't seen a clear answer on how much to tighten the 3 long screws from the inside. How much do I compress gaskets for example?

Also best way or material to caulk around tubes and cups as they go through 1st gasket level. I'm assuming this is critical as a leak here could be serious.

Thanks all

[smithcreek]

Installation instructions state 40-50 inch pounds of torque and the (single) gasket will compress to 1/2".

I'm about to add a second gasket to my 2013 FC20, only came with one from AS. Looks like there is a rear support also on the AC. Anyone know if I need a second set of those also?.

[Steve Bryant]

Originally Posted by smithcreek

Installation instructions state 40-50 inch pounds of torque and the (single) gasket will compress to 1/2".

I'm about to add a second gasket to my 2013 FC20, only came with one from AS. Looks like there is a rear support also on the AC. Anyone know if I need a second set of those also?.

It's been about three or four years since I installed this kit on my Penguin. It has worked flawlessly for me. There are actually two additional rear gaskets that need to be installed. I'm attaching the Dometic installation instructions for the drain kit. The compressed thickness is not listed for the double gaskets, so you'll just have to use an inch pound torque wrench to about 45 inch pounds if you have one. If you don't have the torque wrench, this is about 4 foot pounds (not much). I'd just snug the bolts down evenly and as judiciously as you can and it should work fine.

[A W Warn]

I tightened the bolts until the two gaskets were compressed to 50% of the original height of the two.
It's been 3+ years and there have been no leaks.

[GammaDog]

Originally Posted by bbradb

Also best way or material to caulk around tubes and cups as they go through 1st gasket level. I'm assuming this is critical as a leak here could be serious.

Thanks all

There was a long post on this replacement process about a year ago. (http://www.airforums.com/forums/f427...-182389-7.html) I noted in there that I used Parbond to seal the cut through the upper gasket that is used to pass the tube from each cup. So far, so good. Sealing that is certainly recommended, but not as critical with two gaskets as with one since the lower gasket is uncut.

Other posts in that thread cited use of other sealants. I'm happy that I added a gasket, but that was only one of several issues I had to address. Other posters there had other tales, trick and cautions to offer, too.

[pteck]

I just did this when upgrading, though to a Blizzard NXT.

I personally didn't use any sealant as I didn't my gaskets down to the pan is provided in the instructions. I cut probably 2/3 of the way into the primary gasket, and no wider than the tube. Utilizing the compression of the gasket to seal. Though on does have to be more careful that the compression doesn't result in a pinched tube - which is why the instructions likely say to cut all the way and use sealant. In my case, the rigid cup spout goes partially into the seal which further supports the tube from any potential collapse.

Here's a picture that might help.


As you're tightening, you can see and measure the degree of compression of both gaskets from the inside. I personally didn't go to from full to 1/2 height of the double gaskets. I used a ruler, and took it down to ~60% of the full height.

I could also see sunlight through the tubing to know it wasn't pinched. All sealed up hunky dory in the weeklong rain that followed.

Unsolicited tip:
The stock install in regards to the roof opening was very lacking and probably really compromised performance. You can see in the before picture that there is wiring all through the intake area compromising flow. More importantly, there was nothing blocking hot air being drawn from between the skins (where insulation is poking out). Take the opportunity to use HVAC foil tape and seal around the perimeter in between the inner and outer skins. And tuck the wiring where you can. I went farther (not in this pic) to further insulate around the perimeter.

Original:


After:

[AtomicNo13]

I'm only using 1 gasket with the cups. It works just fine. It's compressed very tight. Zero leaks, no pinching of the drains no contact between cups and roof. Everything works well!