Vacuflush Help

A

Absolutely-Knot

New Member
Aug 21, 2023
6
Boat Info
2007 Sea Ray 52 Sedan Bridge
Engines
2 - Cummins QSM-11
Hello all, ive searxhed and read most all threads on rhis topic and much has helped. I have an issue thatbis cutting my arse. I have two vacuflush systems on my 2007 52 Sedan Bridge. Recently fixed the starboard side with yalls help.
The port side system was working in September but revently stopped working. I found the plunger broken. Took the entire unitnout and put all new duckbills gaskets and new plunger in. Wouldnt pull a vacuum. Took the entire unitnout again and replaced all the new parta mentioned above with new parts. Still wont pull a vacuum. Pumpnjust runs and runs. Rhe toilet holds water so that sealnisnt leaking. All the duckbills are in properly. The lines are not clogged. I have spent so many hours troubleahooting this, it is driving me mad.
Anynideas guys/gals? Im about ready to replace with macerator toilets.
Thanks
Captain Rob
 
When I watched my Tech rebuild my vacuum generators, he said that the O-ring on the plunger as you call it is very tricky. When you put the bellows back in the housing, it has to go in in the proper orientation so that you can bolt it back to the motor. NO TWISTING ALLOWED. Also, the O-ring on the lid of the bellows can be tricky.

Good luck. I hired that sh$t out, LOL.

Jaybeaux
 
Been there.....
2 things to examine. There is a heavier lower seal where the toilet meets the floor. Very common for an air leak there. This is not the upper bowl seal which if bad, would empty your bowl of water. While this is apart check the two O rings on the flush pedal axle shaft. They dry out, Crack and cause an air leak.
 
Did you remove line from head, cap and test? That will determine if the tank unit is working properly and isolate the air leak.
 
Cdn390 said:
Been there.....
2 things to examine. There is a heavier lower seal where the toilet meets the floor. Very common for an air leak there. This is not the upper bowl seal which if bad, would empty your bowl of water. While this is apart check the two O rings on the flush pedal axle shaft. They dry out, Crack and cause an air leak.
Click to expand...
My next step was to pull the hise off the vacuum box, plug it and see if it pulls a vacuum, which would lead to exactly where you said to look, the toilet bottom seal and the seals on the pedal, thank you
 
Cdn390 said:
Did you remove line from head, cap and test? That will determine if the tank unit is working properly and isolate the air leak.
Click to expand...
Thats my next step. That would tell me if the toilet is the source
 
Cdn390 said:
I was so frustrated, at one point I drilled and tapped the hold tank for a vacuum gage. It helped.
Click to expand...
Ok, it's late.....but the holding tank should be at atmospheric pressure...which would read 0.0 psig. Am I missing something?
 
I should have described it as "vacuum generator tank" instead of "holding tank".
 
It amazes me how much time is spent on rebuilding these pumps. Parts are almost half the cost of a new pump. Frustration is equal to the other half. A new pump, 2 wires and 2 hoses, done.
 
Do you have the VG4 vacuum pump? I assume so if you have the 52 sedan bridge which would have the VG4's.
By "rod" do you mean the pump bellows?

First was the VG4 removed and fully cleaned?
There are two duckbill valves under the bellows and two on the discharge line to the holding tank.
All of the duckbill valves point in the direction of flow.
The duckbill valves must be installed dry and their seat ridges must interface with the grooves on the holders.
The threaded discharge fittings must be only hand tight or they will crack the bellows housing which will then leak and require replacement.
There is an O-ring inside of the bellows that the pump top slides into and that can be tricky to get installed with the clamps and motor to bellows alignment. Silicone grease is needed on that O-Ring.
90% or vacuum leaks on these is the O-ring between the bellows housing and tank. Those lower duckbills/spacer, the bellows housing, and that O-Ring must mesh together just perfectly or it will never seal. That O-Ring gets hard over time and must be a standard replacement item. If you are using the four bolts to pull that housing down then it isn't meshing correctly. Those bolts should fully thread in by hand and just need to be snugged down.

Last, sometimes the vacuum switch will develop a hole in the diaphragm. They seem to have about a ten year lifespan.
 
ttmott said:
Do you have the VG4 vacuum pump? I assume so if you have the 52 sedan bridge which would have the VG4's.
By "rod" do you mean the pump bellows?

First was the VG4 removed and fully cleaned?
There are two duckbill valves under the bellows and two on the discharge line to the holding tank.
All of the duckbill valves point in the direction of flow.
The duckbill valves must be installed dry and their seat ridges must interface with the grooves on the holders.
The threaded discharge fittings must be only hand tight or they will crack the bellows housing which will then leak and require replacement.
There is an O-ring inside of the bellows that the pump top slides into and that can be tricky to get installed with the clamps and motor to bellows alignment. Silicone grease is needed on that O-Ring.
90% or vacuum leaks on these is the O-ring between the bellows housing and tank. Those lower duckbills/spacer, the bellows housing, and that O-Ring must mesh together just perfectly or it will never seal. That O-Ring gets hard over time and must be a standard replacement item. If you are using the four bolts to pull that housing down then it isn't meshing correctly. Those bolts should fully thread in by hand and just need to be snugged down.

Last, sometimes the vacuum switch will develop a hole in the diaphragm. They seem to have about a ten year lifespan.
Click to expand...
I did notice the the top part (where the motor and bellows is) sat up a bit when installed. Didn't fit flush to the vacuum box. I didn't recall that on the starboard side when I fixed that. I thought it was because of the new duckbills. I pulled the sleeve out the plastic sleeve put one duck Bill on the bottom, pushed it all the way down and shirt. It was down tight put the other duck bill in the top part with the Bellows put it in and it’s rocks back-and-forth a little late it’s not seated good.
 
bahamabreisus said:
It amazes me how much time is spent on rebuilding these pumps. Parts are almost half the cost of a new pump. Frustration is equal to the other half. A new pump, 2 wires and 2 hoses, done.
Click to expand...
I just checked and a new VG4 system is $1700.00
 
I would make the pump isolation test my top priority. Mid-2000's vintage boats have a reputation for having been built with leaky sanitation hoses. It happened to me about 10 years ago and at the time there seemed to be a rash of the same issue with other boats of similar size and age. In both cases I stubbornly addressed the pumps until I isolated the pump and it held a fine vacuum on its own. I had to replace hoses in both my systems. One end was easy, the other not so much and I had to have it done during a yard period.
 
I had similar problem. Marina said the person was on vacation. I was in ahury to leave so I bought an entire pump think it was $800. Marina would have charged me more than that to fix the unit. Over the next few weeks on the boat I rebuilt the old one. It took a lot of effort and time. Buy a new pump and see if that solves your problem. If it does not you now have a spare pump.
 
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