Sentinel V5, Are there o-rings?

[MrChen]

I bought a used S&S MDX-850 which has the original Sentinel v5 on it (not the xb). It's working and I really enjoy the peace of mind it brings. My worry has been, how do I replace the battery? I searched and searched online and could not find a user manual. I eventually figured out that I can twist the body off and access the 1/3N battery. Now that I'm looking at it, I don't see any sort of o-ring where the body screws tight and you can literally see down into the housing compartment. I wanted to clean and lube it since I separated it. When I tighten it, it doesn't feel like I'm screwing it tight metal to metal. What am I missing?

The top cap doesn't have an o-ring either, but the rubber button could serve as the seal.

I'm referencing this model: Vivid Leak Sentinel V5

 

[MrChen]

I actually see an o-ring on the top cap, it's really small. I need to remove the body again to check there as well.

 

[MrChen]

I've attached a picture of the body removed. I don't see an o-ring with the threads. I tested it and it seals fine.

 

[bvanant]

Isn't the o-ring in the cap?
Bill

 

[MrChen]

Isn't the o-ring in the cap?
Bill

I found the one in the cap, which I mentioned above. What I'm not seeing is an o-ring where the body screws to the housing mount. It doesn't feel like metal on metal, so I'm guessing the housing mount is a different material which allows it to seal.