[C320-list] Access to holding tank pump out and vent connections

[Scott Thompson]

As the creator of this thread I want to comment on some of the answers. 
First, thanks to all that replied. Second, I do not think I have a 
clogged vent. We had the problem even after a pump out when I was 
hearing a rush of air into the vent. At the end of our cruise I pumped 
out again and flushed water into the vent while suction was turned on.  
A lot of water was sucked in and after the inrush of air was again 
audible. Possibly I've had a clog in the past that created a problem. If 
I manage to get access I'm going the route that Jeff suggested of 
replacing the vent with something more substantial. Third, before 
posting I had already done a careful inspection of everything visible 
around the holding tank and head. There is no evidence of any leakage or 
loose connections. This is why I suspect something amiss with the vent 
behind the medicine cabinet. Fourth, someone suggested I pull the 
electrical outlet above the settee for access. On my boat it is just 
above the cushions, and the opening is way too small for an arm. Plus it 
is pretty far from the pumpout fitting on deck or the vent fitting. So 
I'm a bit skeptical that I will make much progress there, but will give 
it a try if all else fails.

Finally, I originally requested some advice for removing the "medicine 
cabinet." I don't think anyone provided tips for doing that. When I 
tried to do so, it became clear that I would need to remove the hoses 
first, and then it isn't clear how you get them back in there 
afterwards. If anyone has thoughts on this process I would welcome them. 
I'm thinking that if I get the thing out I might modify it with a 
removable bottom to make the process easier in the future. Has anyone 
done anything like that.

Scott Thompson

Surprise (#653, 1999)


On 6/3/2019 9:20 AM, Doug Treff wrote:
> I've done the same as Jeff. I'm also in the habit of squirting some fresh water into the vent line before I pump out - In case any debris or insects have taken up residence. The gurgling sound when I pump out after that is evidence that the vent is clear. I still had odor after that job was done. Cured it by switching over to an electric head with fresh water flush. An expensive upgrade but the Admiral is happy.
>
> --
> Doug Treff
> doug at treff.us
>
> On Sun, Jun 2, 2019, at 7:25 AM, Charles Holbrook wrote:
>>   I put a carbon filter in the vent hose just before the line penetrates
>> the hull, behind the medicine cabinet and no more odor.  I got the
>> filter at Walmart in their marine supply section.
>> Charlie #192Port Clinton, Ohio
>>      On Tuesday, May 28, 2019, 1:32:56 PM EDT, Jeff Hare
>> <Catalina at thehares.com> wrote:
>>   
>>   You may have a clog in the vent hose which could have caused the hose
>> to come apart at the vent.  That's accessible behind the medicine
>> cabinet.  Note that the factory used a larger diameter vent hose, then
>> reduced it with a smaller hose inserted in it in order to fit on the
>> vent barb.
>>
>> We replaced the vent hose and vent fitting on the side of the boat with
>> a forespar 3/4" open unit so that the vent would do its job much better
>> without needing to reduce the vent line.  Totally cured the smell when
>> flushing, but then we only use fresh water flush, so that helps too.
>>
>> https://c320.org/mediagallery/album.php?aid=254
>>
>> -Jeff Hare
>>