Thread Tools Search this Thread Display Modes
Old 03-10-2019, 03:59 PM   #1
sbu22's Avatar
City: New Orleans
Country: US
Vessel Name: Panache
Vessel Model: Viking 43 Double Cabin '76
Join Date: Mar 2011
Posts: 1,270
Found the vacuum leak in the sanitary system

A little background: The boat is a 76 Viking. When I got her a few years ago, she still had a few legacy systems. The sanitary system was originally one of the 70s style that serviced two heads. Vacuum transferred waste to an ≈ 40 gallon holding tank. There, through an amazing rat’s nest of wiring that connected to a cover plate with an attached probe, some sort of electrical and magical waste treatment was supposed to occur prior to overboard release. I don’t recall the name of the system – long gone company.

I ripped out the electrical and salvaged the nice F/G holding tank, vac system. Installed new 3 way and hosing. Kept the old but very serviceable commodes. And found that I had a persistent vacuum leak that required the vac pump to run for the system to work. I further discovered that I could eliminate the vac leak by isolating the aft head from the rest of the system. So, I had a performing one head system. That was fine for the limited pax loading that I use. So, the vac leak migrated lower on the “to do” list and stayed that way for a couple of years.

However, the leak was an irritant, so considerable time was spent on an off and on basis chasing it. Several knowledgeable friends gave it a try. Replaced clamps, a valve or two, hose, commode base seal, etc. Still leaked. I finally turned the problem over to the yard I use for stuff I can’t handle. Their old mechanic (guy in his 70s – my age) went straight to the aft head, pulled the commode, and fought with the “funnel” below the deck until he recovered it. The results are shown below.

The funnel has a brass nipple soldered into its outlet. If you look carefully, you’ll see that the nipple is corroded through for 1/16” or so on its lowest elevation (when installed). The hose was double clamped to the nipple, but without sufficient coverage to bridge the gap. All of this is placed where the nipple/hose penetrates a bulkhead, of course.

I don’t know if this arrangement is still around on newer boats – not likely, I think. But, it may be useful info to somebody who’s wrenching an old boat.

Pics 1 and 2 show the general funnel arrangement.

Pic 3 shows the corroded nipple.
Attached Thumbnails
Click image for larger version

Name:	Pic 1 IMG_20190309_144215.jpg
Views:	54
Size:	171.7 KB
ID:	86279   Click image for larger version

Name:	Pic 2 IMG_20190309_144236.jpg
Views:	56
Size:	198.3 KB
ID:	86280   Click image for larger version

Name:	Pic 3  IMG_20190309_144200.jpg
Views:	58
Size:	199.1 KB
ID:	86281  

sbu22 is offline   Reply With Quote
Old 03-10-2019, 04:14 PM   #2
TF Site Team
Insequent's Avatar
City: Brisbane
Country: Australia
Vessel Name: Insequent
Vessel Model: Ocean Alexander 50 Mk I
Join Date: Mar 2012
Posts: 2,649
Nice story!

I had a vacuum leak on the master stateroom head, and when it was very quiet I could hear the leak. So removed everything down to the funnel, cleaned some stuff and replaced a bunch with new Vacuflush parts, and problem fixed.

But the forward head has a leak as well, and no noise that I can detect. But it is likely the same problem. I have the replacement parts, but so far not the inclination to do the tear-down, clean etc. Like you, it is down the list. But I really ought to fix it soon.....

Insequent is offline   Reply With Quote
Old 03-11-2019, 10:45 PM   #3
sbu22's Avatar
City: New Orleans
Country: US
Vessel Name: Panache
Vessel Model: Viking 43 Double Cabin '76
Join Date: Mar 2011
Posts: 1,270
If I'd have just worked the problem aft forward instead of fore to aft, I'd have saved a couple of years. However, this way I've basically rebuilt the system.
sbu22 is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -5. The time now is 10:30 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012