Bounder: Well I thought it worked. 35k rebuilt vacuum pump pumping but not creating vacuum

[mrsportys]

Ok we went they the whole “ nobody wants to do this job” so I rebuilt the pump myself.
Cleaned,sanded all. Duckbills in place as in diagram, bellows and gaskets in place.
Toilets filled with clean water. With pump operating neither toilet flushes
The questions I have are, 1) does the bellows need to be primed?
2) per the picture, part number 1, the cover fits above the bellows, the area below with the bellows is not sealed, so how does this create a vacuum?
Pump just keeps running, water in both toilet bowls, even opened up black and grey tanks ( relief pressure?)
Not a genius but need some help.
Thanks!
35k 2014 bounder

[mrsportys]

Originally Posted by mrsportys

ok we went they the whole “ nobody wants to do this job” so i rebuilt the pump myself.
Cleaned,sanded all. Duckbills in place as in diagram, bellows and gaskets in place.
Toilets filled with clean water. With pump operating neither toilet flushes
the questions i have are, 1) does the bellows need to be primed?
2) per the picture, part number 1, the cover fits above the bellows, the area below with the bellows is not sealed, so how does this create a vacuum?
Pump just keeps running, water in both toilet bowls, even opened up black and grey tanks ( relief pressure?)
not a genius but need some help.
Thanks!
35k 2014 bounder

[mrsportys]

Originally Posted by mrsportys

Attachment 332134Attachment 332135

So how is a vacuum created if the bellows is open to the outside?

[Florida Rang]

What does a New pump cost ? Is it more than your stated $35 K to rebuild yours .

[US1]

Originally Posted by mrsportys

So how is a vacuum created if the bellows is open to the outside?

The vacuum is created below the bellows within the lower part of the housing, thus why the top is open. Its the up/down motion of the bellows that open/close the duck bills. There is no sealing (to a degree other than part #7), but a displacement of air. Just like a piston in gas motor going up down, the intake(vacuum) and compression all happen in the top part of the cyl with the valves acting like the duckbills, while the area beloow the piston rings is open to the oil pan area. Only difference is the vacuum pump is upside down when compared to a gas motor.

Is the toilet bowl seals and ball valve good/closing fully? All connections and duckbills fittings tight? No cracks? A small air leak will cause the pump to run continuously. Is the vacuum switch sealed/stuck? Duckbills in correct direction all going same direction?
I have never had to prime mine. The cover is just to keep fingers and whatnots clear of the rotating bellows motor shaft. Nothing more.

[RRR]

Does it ever build a vacuum?

My first thought is the duckbill valves are backwards. Stuff needs to flow through them.

[mrsportys]

Originally Posted by Florida Rang

What does a New pump cost ? Is it more than your stated $35 K to rebuild yours .

$700-900

[mrsportys]

Originally Posted by US1

The vacuum is created below the bellows within the lower part of the housing, thus why the top is open. Its the up/down motion of the bellows that open/close the duck bills. There is no sealing (to a degree other than part #7), but a displacement of air. Just like a piston in gas motor going up down, the intake(vacuum) and compression all happen in the top part of the cyl with the valves acting like the duckbills, while the area beloow the piston rings is open to the oil pan area. Only difference is the vacuum pump is upside down when compared to a gas motor.

Is the toilet bowl seals and ball valve good/closing fully? All connections and duckbills fittings tight? No cracks? A small air leak will cause the pump to run continuously. Is the vacuum switch sealed/stuck? Duckbills in correct direction all going same direction?
I have never had to prime mine. The cover is just to keep fingers and whatnots clear of the rotating bellows motor shaft. Nothing more.

Talked to Troy at marine sanitation in state of Washington. I explained the 1-2-3 directions they had attaching bellows and gasket below. He agreed they were incorrect. They didn’t even show replacing bellows clamps.
Talked it thru. Reseated everything. Because some of the pipe work down there is rigid I want to reset seeped into pipes. Got it to vacuum once not the next time so I’ll be making sure gaskets inside are clean.
Troy from MS did say the pressure to get all together would be intense. I did “soften” up the bellow to be a little more flexible by putting under warm water for a minute.
I’m 95% of the way there.
Thanks all

[mrsportys]

Originally Posted by RRR

Does it ever build a vacuum?

My first thought is the duckbill valves are backwards. Stuff needs to flow through them.

I replaced the duckbills as per the diagram. They seated nicely.
Doesn’t look like I can attach diagram but I did in previous posts

[RRR]

Using your diagram in post #2 the inlet would be coming in the left side.

You said that it built vacuum once? But then not again?

[mrsportys]

Originally Posted by RRR

Using your diagram in post #2 the inlet would be coming in the left side.

You said that it built vacuum once? But then not again?

Correct. Seated nicely. Grandkids leaving this afternoon going to play with again.
Thoughts on duckbills?
Going to check gaskets and water in toilets.
Thanks for thoughts!

[77Travco]

Put your hand over the intake side of the vacuum generator and verify it's building vacuum. Does it eventually shut off if you block the intake side? If so then the leak is upstream between there and the toilet valve seal.

[mrsportys]

Originally Posted by 77Travco

Put your hand over the intake side of the vacuum generator and verify it's building vacuum. Does it eventually shut off if you block the intake side? If so then the leak is upstream between there and the toilet valve seal.

Left of the vacuum pump or right?
What part is the vacuum generator?

[77Travco]

Originally Posted by mrsportys

Left of the vacuum pump or right?
What part is the vacuum generator?

The "vacuum generator" is just my term referring to the entire vacuum unit that lives down in the basement. Left or right depends on how yours is mounted. I'm talking in terms of in and out of the unit. Hope that makes sense.