2003 Mainship 400 sanitation hose replacement

[Hydrospud]

Our 2003 Mainship 400 holding tank lines need to be replace due to odor. Does anybody know how to access the hose that is connected to the toilet? The hose runs from the Vacuflush unit through a bulkhead under the shower then to the toilet. This whole setup is blocked by a main stringer that runs between the holding tank and the bathroom. Can I remove the toilet and lift the toilet mounting component to remove the hose?
Any help would be greatly appreciated. The attached picture shows the where the hose runs from the Vacuflush unit into the bulkhead.

 

[Comodave]

Not familiar with your boat but I am doing the hose replacement along with getting rid of the Vacuflush head. I took the head out yesterday. I will be putting in. Marine Elegance head and using 1” discharge hose, Raritan SaniFlex hose. The new hose is 1 3/8” OD. So I am going to try sending it through a couple of sections of the old 1 1/2” hose. The 2 areas are inaccessible and so hopefully with a pull line and a lot of wire pulling lubricant I will be able to slide the new hose through the old hose. I cleaned out the old hose with a mixture of laundty detergent and sodium personate before we hauled the boat. When you put in the new hose only use the SaniFlex hose. Defender sells it by the foot. Good luck.

 

[Hydrospud]

Thanks

Comodave
Appreciate the input. Good luck with your hose pull. I'm sure with a few bloody knuckles your GET-ER-DONE!

 

[Shrew]

I don't see how you could do this without removing the existing head.

 

[Comodave]

I wasn’t sure if I was crazy to think it might work so I asked Raritan tech support if they had ever heard of anyone doing it and he said that he had. Said he had several people tell him they had done it. So I guess that it may work if the old hoses are clean enough. Time will tell.

 

[Shrew]

I wasn’t sure if I was crazy to think it might work so I asked Raritan tech support if they had ever heard of anyone doing it and he said that he had. Said he had several people tell him they had done it. So I guess that it may work if the old hoses are clean enough. Time will tell.

LOL, I meant to the OP. However, for your idea, as long as there is enough of a gap between the ID of the 1-1/2" and the OD of the 1", and provided the line is clean and lubed well, I can see this working.

It would only be the case with a line used exclusively with a freshwater flush. There'd be too much calcification on the interior of a raw water flush system that spent a good deal of time in saltwater.

 

[Comodave]

My boat is freshwater and the head is freshwater flush too. It is surprising how different a freshwater boat is from a salt water boat in general.

 

[Bmarler]

The vacuflush hose outlet can be on the bottom, or the rear typically. If you don’t see it coming out the back you’ll need to unscrew it and lift it up to access the hose. The big issue with changing out the hose will be if it’s clamped in an inaccessible area. Good luck with it, it’ll be worth it in the end.

 

[Dougcole]

I am also about due for this same job on our '05 400. I have not done it yet, but I have a plan and I have done a lot (way too much) work on the head system on our boat so I know a few things that may help you out.


Also, there is some info on this exact job in another current thread called "hose replacement" it may be helpful to you as well. Here is a link:
https://www.trawlerforum.com/forums/s11/hose-replacement-39537.html



1. Yes, you need to take the toilet out to access the head end of the hose. It is attached to the bottom of the toilet on what VF calls the "funnel." I had to replace the funnel on my toilet, so I am familiar with the set up. There is probably not much play in the hose under the toilet, but after I disconnected the VF end from the VF generator I was able pull the hose toward the toilet about a foot. I am hoping that this means the hose is not zip tied in so tight that it won't slide.


2. Remove the entire VF generator unit (flush it quite a few times first) to get it out of the way. It's easy, just take off the inlet hose, which is on the fwd end in your pic, and the outlet hose. Then disconnect the wires, of which there are only two. Then remove the four screws holding it down and pull out the unit.



After it is out you will have good access to the aft end of the hose.


From here, all I have is a rough plan. I hope to be able to glue the new hose to the old hose with a double male adapter, grease up the new hose and use the old one to pull it through. I think pulling the hose from the head into the storage area under the helm will be easier, but I am not sure about that.


In the other thread, Mermaid said her boat has an access plate under the sink in the head, which may allow you to reach some, or all, of the zip ties if the hose won't pull through. My boat does not have this plate, but it would be a good spot to cut one if needed.


If that doesn't work, maybe an access plate in the bulkhead under the helm?


Please post and let us know how this job goes for you.


Thanks and good luck.


Doug

 

[bgillroy]

We replaced both VF with marine elegance on Peggy Halls advice...6 years no problems. We wired end of new to end of old and pulled it through. Two man job. You go with Raritan marine elegance upgrade you can downsize hose diameter by inch or more and do away with huge VF vac unit.