Black Tank Flush Hose Connection

[racerx1699]

Our black tank flush hose connection started leaking yesterday. Does anyone know where I can get this part from? We are traveling a lot right now so I need an online source so I can have it shipped to our location. We are just out of warrantee so I don't think Grand Design would send me one. Has anyone had to change this part yet?

[steve&renee]

Our black tank flush hose connection started leaking yesterday. Does anyone know where I can get this part from? We are traveling a lot right now so I need an online source so I can have it shipped to our location. We are just out of warrantee so I don't think Grand Design would send me one. Has anyone had to change this part yet?

You're not gonna like this response. I was having issues with my fresh water inlet connection. That part is indeed available:

https://www.amazon.com/gp/product/B082FYZBW4/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

But when I was having issues with my blank tank flush and I called B&B Molders (574-259-7838), the guys that make the Nautilus, they (sheepishly) told me the black tank flush was not designed to be serviceable. They said they were having some regrets about that now. . .

Anyway, you might consider getting one of those hose adapters with a shutoff valve built-in. Add a couple of soft hose washers on the black tank fill side and tighten well.

Good luck.

-Steve

[Cate&Rob]

Our black tank flush hose connection started leaking yesterday. Does anyone know where I can get this part from? We are traveling a lot right now so I need an online source so I can have it shipped to our location. We are just out of warrantee so I don't think Grand Design would send me one. Has anyone had to change this part yet?

A black tank flush connection does not have a check valve (by design). When you disconnect the flush hose, the high mounted vacuum break opens and the water in the line drops into the tank on the tank side and out the inlet port on the hose side. Leaving the flush line empty. I think your flush line is working as it should .

Rob

[ckreef]

I've always had a hose adapter with shutoff valve attached to both the water inlet and the black tank flush. Just never liked the idea of screwing metal into those plastic fittings over and over again.

[steve&renee]

I've always had a hose adapter with shutoff valve attached to both the water inlet and the black tank flush. Just never liked the idea of screwing metal into those plastic fittings over and over again.

Excellent advice. The plastic fittings DO wear out over time coupling to metal. Until I replaced mine, the plastic threads had worn so much that the hoses wouldn't stay put. Definitely recommend using an adapter.

[Cate&Rob]

I've always had a hose adapter with shutoff valve attached to both the water inlet and the black tank flush. Just never liked the idea of screwing metal into those plastic fittings over and over again.

For the black tank flush vacuum break to work properly, there should not be a valve on the inlet. The water must be allowed to drain back out to establish an empty line which prevents the potential for contamination to migrate through standing water which could be held in the line by a valve.

Rob

[Tom in PGH]

I attached a 90-degree brass elbow to both the fresh-water and flush connections. This allows for less strain on the connections and I am able to hook my hose to the metal connection. I’ve only hooked to the plastic connection once for each fitting, and that was to hook up the elbow.

[ThePowells]

Donnie, Reach out to customer service anyway. You might get a surprise.

[racerx1699]

The connection only leaks when I have water running to flush the tank, I think I may have cracked it when I connected the hose. I have found the parts from B and B molding, I should have looked in my owners manual first Thanks

[ckreef]

The connection only leaks when I have water running to flush the tank, I think I may have cracked it when I connected the hose. I have found the parts from B and B molding, I should have looked in my owners manual first Thanks

It's really easy with those plastic fittings to connect to them just not right and have them leak. Before I started tearing things apart I would get a new hose gasket and a 45° or 90° metal adapter (with or without valve). Very carefully screw the adapter on (with new gasket) and a hose and see what happens.

My fresh water inlet was good. Then I reconfigured things and had to unscrew and screw my adapter back in. It leaked crazy. I then took the adapter back off, made sure the gasket was sitting right then carefully screwed it back on. The leak was gone. I'll never unscrew that adapter again.

$60k trailer and they use crappy plastic hose connections. Saving a few dollars. What were they thinking?

[ckreef]

For the black tank flush vacuum break to work properly, there should not be a valve on the inlet. The water must be allowed to drain back out to establish an empty line which prevents the potential for contamination to migrate through standing water which could be held in the line by a valve.

Rob

I do understand what you are saying. Just open the valve for a few seconds after removing the hose and the problem you describe is solved. I use a dedicated black flush hose so the issue of contamination is really not there.

Of course you could always use a metal adapter without valve. Either way constantly screwing a hose onto that plastic fitting is not a great idea.

[steve&renee]

... Either way constantly screwing a hose onto that plastic fitting is not a great idea.

Exactly. In fact, my fresh-water plastic fitting failed. Get yourself an adapter.