Diagnose leak in Head System

Todd320

Todd320

Well-Known Member
Jul 21, 2016
1,508
St. Petersburg, FL
Boat Info
2007 Sea Ray 320DA
Engines
Twin V-drive 5.7L 350 Horizon
I have a VacuFlush head system on my 07 320, the pump would run constantly since the midway part of my last trip, so I purchased new duckbills and bellows and o-rings. Replaced all, and initially, same issue, but realized I missed an o-ring, fixed that, and now it builds up a vacuum, but then loses it 10 seconds later, pump runs for 5 seconds, then 10 seconds later starts again. So, to determine if it was a problem from the hose connection to the toilet, I removed the hose from the toilet, (important note, I had removed it as part of this process anyway, although it did not need to be removed), when I placed my hand over the hole and turned on the pump, it stopped running 60 seconds later, and stayed off for the 2 minutes until I removed my hand (no hickey! Actually, used a thick rubber glove, so the glove expanded, not me). So, I know the vacuum tank is perfect, and my installation of the bellows and duckbills were correct. The issue must be between the connection to the vacuum tank, and the toilet. Note, the toilet has water and did not leak at all, remained constant volume. My first guess is the connection to the tank, my theory is I did not do it right, or the o ring is bad. My understanding is I should simply hand tighten the nut (connecting the hose from the toilet to the tank) and then turn it 1/2 turn with a wrench, which is what I did. Aside from checking the o ring, is there anything else that I should do? Use any type of tape or sealant, follow a different procedure? As always, thanks for your help...

If it is not the connection, then could the hose be bad and allowing air to come through it? It does not seem to be the toilet, since it holds water, so the seal at the top of the bowl seems fine, but is there another way for air to get in below the flap/ball that holds the water?
 
Todd320 said:
I have a VacuFlush head system on my 07 320, the pump would run constantly since the midway part of my last trip, so I purchased new duckbills and bellows and o-rings. Replaced all, and initially, same issue, but realized I missed an o-ring, fixed that, and now it builds up a vacuum, but then loses it 10 seconds later, pump runs for 5 seconds, then 10 seconds later starts again. So, to determine if it was a problem from the hose connection to the toilet, I removed the hose from the toilet, (important note, I had removed it as part of this process anyway, although it did not need to be removed), when I placed my hand over the hole and turned on the pump, it stopped running 60 seconds later, and stayed off for the 2 minutes until I removed my hand (no hickey! Actually, used a thick rubber glove, so the glove expanded, not me). So, I know the vacuum tank is perfect, and my installation of the bellows and duckbills were correct. The issue must be between the connection to the vacuum tank, and the toilet. Note, the toilet has water and did not leak at all, remained constant volume. My first guess is the connection to the tank, my theory is I did not do it right, or the o ring is bad. My understanding is I should simply hand tighten the nut (connecting the hose from the toilet to the tank) and then turn it 1/2 turn with a wrench, which is what I did. Aside from checking the o ring, is there anything else that I should do? Use any type of tape or sealant, follow a different procedure? As always, thanks for your help...

If it is not the connection, then could the hose be bad and allowing air to come through it? It does not seem to be the toilet, since it holds water, so the seal at the top of the bowl seems fine, but is there another way for air to get in below the flap/ball that holds the water?
Click to expand...

thse problems are a royal PIA. I chased one on my old boat and bit the bullet and ordered the vacuflush tester. It wasn't cheap (considering what it is - a big stopper with a vacuum gauge) but it makes troubleshooting easy because you can leave it in place as you work your way back from the vac generator ultimately to the toilet. Might be worth an investment -

https://marinepartssource.com/domet...AyC1N7Dxu0RCJVtd-ooUF3ODI-gdXOmhoC1nYQAvD_BwE
 
E01E1693-99B0-4FEE-9156-82CCBC55DE16.jpeg
There are two o-rings on the ball shaft that connects to the water valve. I chased a vacuum leak forever and finally found it there. O-rings went flat
 
@920richardf and @Shenanigans77, Thank you, so the o-rings in the image below, circled on the brass piece? I'll just buy the kit pictured (once I verify it is the correct one for my bowl), plus the seals (since, I haven't done those yet, but surely they will start to leak next...), and that will be a good first step...

Screen Shot 2020-09-27 at 9.40.08 PM.png
 
everyone has had a gremlin in the head system-complete rebuild-still lost vacuum-the pvc part called the dipt tube -goes into the holding tank-had a hair line crack in the connection -someone must have used wrench or channel locks to tighten-once the I installed the new -worked great-of course it was the last thing to check-marinediscounters -theDoc-was a big help-good luck!
 
Just replaced mine (dip tube), but it had dry rotted/deteriorated over the years, hard to believe it was still working when it fell apart. I just touched it and poof

strange weather said:
everyone has had a gremlin in the head system-complete rebuild-still lost vacuum-the pvc part called the dipt tube -goes into the holding tank-had a hair line crack in the connection -someone must have used wrench or channel locks to tighten-once the I installed the new -worked great-of course it was the last thing to check-marinediscounters -theDoc-was a big help-good luck!
Click to expand...
 
The holding tank does not have a vacuum (duckbills leading to the tank prevent this), so cannot be part of the problem, the vacuum tank does, I am guessing the vacuum tank has this dip tube? That would not be my issue though, since the vacuum tank is 100% perfect and did not leak when tested after removing the toilet input and blocking it.
 
Todd320 said:
The holding tank does not have a vacuum (duckbills leading to the tank prevent this), so cannot be part of the problem, the vacuum tank does, I am guessing the vacuum tank has this dip tube? That would not be my issue though, since the vacuum tank is 100% perfect and did not leak when tested after removing the toilet input and blocking it.
Click to expand...
Yes, the dip tube I had an issue with was on the vacuum tank, before the holding tank.

I agree, if the vacuum held fine with the rubber glove over the hose at the toilet, the issue is at the toilet....
 
I replaced mine over the weekends, but did not do the o-rings, nor did I grease them when putting in the new duckbills. Prior to replacing, the water had drained out of the bowl a couple of times, but now it seems to hold water. The issue is that the vacuum still runs every 5-10 minutes. What are your recommendations? I was thinking about replacing the bowl seal next, but if I missed something with the o-rings, should I start there again?
 
Misterhelms said:
I replaced mine over the weekends, but did not do the o-rings, nor did I grease them when putting in the new duckbills. Prior to replacing, the water had drained out of the bowl a couple of times, but now it seems to hold water. The issue is that the vacuum still runs every 5-10 minutes. What are your recommendations? I was thinking about replacing the bowl seal next, but if I missed something with the o-rings, should I start there again?
Click to expand...
If the bowl is holding water, it’s probably fine on that end.

may be the tank end, there could be a leak, the duck bills could need replaced, the bellow could need it also
 
Misterhelms said:
I replaced mine over the weekends, but did not do the o-rings, nor did I grease them when putting in the new duckbills. Prior to replacing, the water had drained out of the bowl a couple of times, but now it seems to hold water. The issue is that the vacuum still runs every 5-10 minutes. What are your recommendations? I was thinking about replacing the bowl seal next, but if I missed something with the o-rings, should I start there again?
Click to expand...
If you're leaking water out of the bowl then change the ball seal. You dont even need to leak very much water out for the vacuum pump to kick on.
 
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