Connecting black and grey tank outputs?

[21GFamily]

Hi there! On our 21G there are separate drains for black and grey tanks, meaning I have to unhook the drain hose from the black tank and then move it to the grey tank drain. Not a giant deal but it’s something I don’t like. Has anyone had success in connecting the plumbing so that there’s just one drain?

Thx!


2020 GMC HD3500 Denali Duramax SRW
2021 Momentum 21G

[A.Texas.Yankee]

Hi there! On our 21G there are separate drains for black and grey tanks, meaning I have to unhook the drain hose from the black tank and then move it to the grey tank drain. Not a giant deal but it’s something I don’t like. Has anyone had success in connecting the plumbing so that there’s just one drain?

Thx!


2020 GMC HD3500 Denali Duramax SRW
2021 Momentum 21G

Yes. Quite a few have done it, but you want to make sure you tie in after the termination valves and have your drop the right pitch to drain correctly.

All About Rvs did this to his 5th wheel on YouTube. I've contemplated it myself, but in the end decided to run two lengths of hoses with a Y.

Newly full timing in our 2021 Momentum 395MS-R with our tow pig being a 2021 F-450 KR