SO419 Holding tank hoses

[Beam Reach State of Mind]

We discovered this past weekend that the joker valves and hoses on our 5 year old boat, bought by us last year, have never been changed our cleaned out. Crud had calcified within the joker valve fitting, the macerator housing (we have the Jabsco electric Quiet Flush heads), and within the discharge hose to the extent that the heads were blocked.

After much disgusting work I have been able to break out a lot of the calcified solid material; but I still don't have all of it because I cannot get all the way up the discharge hose from the joker valve to the top of the holding tank. Even more puzzling is that I cannot trace the hose from where it disappears into the liner behind the toilet to where it appears - presumably - feeding into the top of the tank. There must be a fitting somewhere because they are different size hoses - the fitting on the top of the tank has a much bigger hose than what comes out the back of the toilet.

I know this hose must be accessible because everything I read says they need to be replaced after a while because they become odor permeable. Any and all advice is appreciated!

[bereboot]

Vinegar dissolves the crust (if not to much) you can always try this.

[Beam Reach State of Mind]

Update: I was able, in the aft head, to find a check valve that also served as a reducer (expander?) between the 1" hose coming off the toilet and the 1.5" hose going to the tank. It was reachable from inside the head compartment under the washbasin, and I was able to maneuver the entire hose out from the toilet back to under the washbasin, where I was able to disconnect the hoses from the check valve.

I discovered that both the 1" hose and the check valve were completely plugged up with the crust, which I had to chop out - I think it's way past the point where vinegar would work. I reinstalled everything but it's still not flushing hardly at all - I think the 1.5" hose needs cleaning/replacing also. I have to figure out how to get it out.

As for the forward head, I now know what I'm looking for, but am still at a loss as to how to get access to it.