Replacing the tank vents
We decided to change out our old Vacu-U-Jet roof vents for some newer style 360 Siphon vents. The existing vents work well when going down the road, but they are directional in nature, not 360. Ours also had damage to the venturi cone, so they needed to be addressed, so a good time to try something new.
All the instructions and videos that I found online were for, what is now, the Generation 1 vent. What is currently shipped is Generation 2. I believe Gen 2 came out when Lippert acquired the product. Generation 2 claims to have a more effective siphon design.
It is also smaller, does not come with any sealant, screws, or the glue needed to assemble the parts (shrinkflation). As an added bonus, it comes with a set of poor instructions. Searching online, I was eventually able to find a set of complete Gen 2 retrofit instructions which was a help.
Installation
Part of the Gen 2 update was to be a better retrofit for existing vents by simply changing the old vent top with the new siphon top. The manual shows how to retrofit the Vac-U-Jet, however that seemed like more work which is why I followed the complete installation version. Other style vents appear to be a very easy change-over which saves you form breaking the existing seal or dealing with new/old mounting screws.
The old vents had several chips and were brittle from years of UV exposure. Instead of replacing them with the same, I changed them to the “360 Siphon”, which gets lot of good feedback on various forums.
Remove the screws and then pry off the vent by slowly working around the perimeter with a stiff putty knife (5in1 works great). After removal, there were a few “extras” that had found there way inside, leaves, bugs, etc.
Clean off the area and remove all of the old sealant. The new 360 vents would not fit over the existing ABS vent tube due to the silicone that was used between the ABS tube and the roof cutout. I had to trim the silicone back ~1/4” to allow the new base to fit.
The new base did not cover the old screw holes, so those were chamfered and filled with marine grade epoxy. They will also be covered by some Dicor lap sealant. If you don’t like Dicor then Heng’s Self leveling silicon would be an excellent choice. I would choose the Hengs over the Dicor but other areas already had Dicor and I did not want to have multiple types of lap sealants on the roof.
Apply your sealant of choice and secure it with screws (pre-drill the holes to help minimize surface cracks). I filled the gaps between the base and the ABS vent with silicone, not necessary (with the new vents) but was easy to do.
The 360 vent has a small funnel that fits between the ABS vent pipe and upper cap (see attached manual). That funnel is glued into the cap and the cap glued to the base. The manual’s recommended glues are: House Hold Goop, Sikaflex 221, 3M 5200, or equivalent.
Time will tell how well these work and how durable they are, if I don’t like them easy swap back to a Vac-U-Jet.
