What is the Max Outer Diameter of the SilverBack RV Sewer Hoses w/ 3" Swivel Fittings

Updated 10/30/2025 | Published 02/18/2025

Question:

What is the outside diameter of the fittings on the Greyback hoses? Want to know if they will fit in the bumper of my Casita. Thanks!

asked by: Bob W

Expert Reply:

Hey Bob, thanks for reaching out!

The fittings on the SilverBack RV Sewer Hoses w/ 3" Swivel Fittings # D04-0675 are industry standard so you're looking at a max outer diameter of 4-1/8" (although sometimes it can be a little less). As long as your bumper can accommodate at least 4-1/8" then you'll be good to go!

Anything else I can help you with?

expert reply by: Jon G

Jon G.

10/30/2025

Hey Bob, how did the fit of the SilverBack sewer hoses work out with your Casita’s bumper? Knowing if that 4-1/8-inch diameter cleared the space could help others checking their setups too.

Bob W.

10/30/2025

@JonG I ended up going a different route because it seemed liked they wouldn't fit. I bought the Rhino set-up, and a larger Camco tube that I strapped to the front of the Casita. The old smaller hose is still in the bumper, and I bought a fitting for it to hook to the Rhino when I need a longer run. The Rhino works really well, so it worked out great all around. Bottom line: most of the better hoses won't fit in the Casita bumper.