Holding tank Volcano!

quality time said:
Keep in mind that vacuum pumps use four duckbills, the macerator uses two.
Click to expand...

Looking around...the T style pumps look like usually white plastic and the S vacumm black plastic. I wonder if PO installed a T top onto an S bottom. T's are 1/2 the price...money saving move?

Guess I'll know when I break it down. I have 4 each 1-1/2" and 2" duckbills.
 
EDIT: Looks like we were typing at the same time!

"T" = Transfer/discharge (macerator, even though it's not an actual macerator). "S" = Suction (vacuum).

Actually, it kinda looks like you have a combination of things there. Typically the S-series is black and the T-series is white. There's no difference in the motor - it's the base that differs from one series to the other. It looks like you have a S-series base with a newer motor from a T-series. I can't tell too well from the picture angle, but when you open it up you "should" have 4 duckbills if what I am thinking is correct.

I'm only guessing, but I would imagine that a T-series would work - it still operates under the same principle - but probably not as well.

The relief valve started being used, I think, somewhere in the early to mid 2000's. But even so, it may not have been the same year for all model boats. Cliff, the other thing going on here is that you have a 28-gallon system, while DTFLD's is a 40-some gallon tank.
 
That is your forward head vacuum generator assembly with the wrong pump installed on it. The Macerator or discharge pump should be installed atop the holding tank further aft (if you have a macerator (TW) pump). The TW pumps are not designed to develop a vacuum but rather simply transfer from the holding tank overboard; there are only a single inlet and single outlet duckbill valve on these TW pumps. There is a switch integrated with the waste thru-hull valve so that unless that valve is opened the macerator will not operate. Operationally, when the head is flushed the vacuum in that little tank is released pulling the waste from the head towards the tank. That switch installed on the tank senses loss of vacuum and starts the pump which transfers waste from the little tank to the holding tank and at the same time creates a vacuum in the little tank up to the head and ready for the next flush. And another note - once liquid waste gets into the holding tank vent filter it's trash and needs to be replaced. If you take care of the system the filters last a long time.
The disc valve atop the holding tank is a vacuum breaker so when draining the holding tank it does not collapse. It is not a pressure "relief valve".
https://www.environmentalmarine.com...erators-and-pumps/vacuum-generator-2-vg2.html
 
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CliffA said:
interesting....do all holding tanks have this relief valve?.....I have worked on my waste system several times and I don't recall seeing a valve like this on my holding tank.....I would assume it is located on top of the tank....correct?....

cliff
Click to expand...
Hi Cliff,

My '05 340 did. I never looked on my 410, and my 58 has the genny on top of the HT, so I may never know! Actually, when I have to crawl behind the genny, I'll look for it...
 
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Damn.... Boat black water plumbing just sucks... I hate plumbing!!... I know this post doesn't help but that's kind of your fault with the "Holding tank volcano" title... It's like a car accident you have to look.

Good luck killing that fountain!!...damn!
 
I think more going on here than operator error. Head was supposed to be pumped, but I could verify. Tank sensors inop, on list of things to do.

Boat sparingly used over the last year, and I think tank not really holding 42 gal, more like 10 from solids dried in tank.

Bottom line who knows, but gotta used it to find these things out.

No big deal...just boating.
 
Replaced the filter (relocation to more accessible location pending), and confirmed this is an S style pump with a T motor. Replaced 4 1-1/2” duck bill valves. Cracked the dip tube assembly and had to replace that with a new but much more robust part. Vacumm generator working like new, but I think the vacumm switch isn’t set correctly (no cover) and don’t know if P.O. messed with it. They claim they are factory set and not field serviceable, so I’m replacing that too.

Still have to get the level switches working or add a 3rd party system to monitor the system level, and replace the negative pressure relief valve. I got my hand on it and could feel a pile of rust where a screw should have been.

Hopefully I have a like new system after all this.
 
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Replaced the vacuum switch tonite and front head is back and working very well.
 
Happiness is...

A set of working tank monitor switches!!

Pulled and cleaned them. Added spade connectors to the wires so future removals are easy.

Someone flushed a clorox wipe. Hopefully thats all. I added a good amount of Tide laundry detergent and filled 1/2 way. I'll let that slosh around for a couple days and pump out when I arrive next week.

IMG_0302.JPG
 
Well. Almost there. The front vacuum pump is running every 7:30 min/seconds after I replaced the vacuum switch. Great vacuum, pump runs too much

A couple google searches seem to indicate a faulty vacuum relief valve as Carter discussed earlier. It’s about the only thing I haven’t replaced.

Unless I need to put some more greas on the vacuum switch rings?
 
Or there is a slight leak somewhere.

Could be at any fitting, could be a pinhole in a pipe, could be one of the 4 seals in the bowl
 
Might consider replacing the spring assembly for the flush pedestal. It has an o-ring that can go bad and cause cycling, just another point of vacuum failure in the system.
 
I don’t suspect the bowl, it holds water and hasn’t been an issue up till now.

I replaced 4 duckbills, had to replace the dip tube assembly, and replaced the vacuum switch. Once I replaced the vacuum switch it when I started having issues with excess running.

The vacuum switch comes with some type of grease on the orange. Is that standard petroleum jelly? Might I need to add more?
 
I dont have a vacuflush and know nothing about them but I have had that happen to me with a regular head. The holding tank wastnt nearly filled. The problem was the vent line was clogged. Once I unclogged the vent line the head was fine and opening the deck plate did not cause a volcano.
 
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