Vacuflush Pump rebuild technique?

dtfeld

Water Contrails
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Jun 5, 2016
5,518
Milton, GA
Boat Info
410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
Engines
Cat 3126 V-Drives
I have my vacuflush pump out of the boat and rebuilding it on the bench with new bellows and duck bills. No instructions that I can find. I have a couple questions.

1. Does the bellows bolt need any lubrication/grease? If yes what kind?
2. Lube the orings or replace dry?

Dave
 
I use dish soap for both. The only thing I will say with the bellows bolt is the motor needs to be rotated in a straight up and down position so it’s not cockeyed when you’re putting it together. You should have 2 o rings. One for the pump housing and 1 on the bellows.

muratic acid is you friend when cleaning all that.
 
I have my vacuflush pump out of the boat and rebuilding it on the bench with new bellows and duck bills. No instructions that I can find. I have a couple questions.

1. Does the bellows bolt need any lubrication/grease? If yes what kind?
2. Lube the orings or replace dry?

Dave
Dave,

I used silicone grease on all O Rings and the base of each duckbill - which acts like an O Ring. The first one I rebuilt I did not use any and the pump ran every couple of minutes. Redid it with the silicone grease and no problems. Needless to say, clean all the surfaces well before reassembly.

You can get it in the HD plumbing section (get two tubes - they are small - $3 each) or order it online...
 
And don’t forget: handtight fasten is more then enough.
Also don’t forget the 2 o rings in the ball shaft in your toilet and the 2 big seals :)
 
If you are doing the toilet seals always do the ball at the same time. The old ball will take out the new seals in no time.
 
and I cracked the body...

I think this is an S body? Dometic website shows a different color/material? Maybe an improved design LOL!

Going to buy the fitting as well, PO used some kind of pipe dope all over thus stuff.

20191207_132135.jpg
 
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And don’t forget: handtight fasten is more then enough.
Also don’t forget the 2 o rings in the ball shaft in your toilet and the 2 big seals :)

Now I see this...
 
Updating the motor to the new longer style and changing out the bellows was one of the best things I did. Unit now cycles in about 45 seconds or less. Pretty fast fix, wear gloves.
 
S body = suction = vacuum.

T body = transfer = overboard discharge.

The difference is in the number of duckbills.

Where is it cracked? Fixable?
 
Yeah, I don’t see the crack, maybe you can plastic weld or epoxy? The vacuum is held beyond the bellows in the tank so if you can seal it up I bet you’ll get away with not replacing the housing. I’m sure that Part is not cheap
 
Honestly it’s best just to buy the entire pump instead of the housing. It will cone assembled and now you have spare parts.
 
Cracked on the mold part line on the inlet. I used some JB Weld and Ill put a clamp on it once dry. Part is about $100. New pump $750:(, $585 without motor. Ouch.

Crack.PNG
 
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I could have sworn I paid 399.00 for the entire thing motor included. I’m mobile at the moment so can’t look it up but I really think 400 gets you a whole new pump.
 
I could have sworn I paid 399.00 for the entire thing motor included. I’m mobile at the moment so can’t look it up but I really think 400 gets you a whole new pump.

for $400 thats more interesting.

Honey! Guess what I want to Xmas? Poopy Potty Parts!!
 
and I cracked the body...

I think this is an S body? Dometic website shows a different color/material? Maybe an improved design LOL!

Going to buy the fitting as well, PO used some kind of pipe dope all over thus stuff.

View attachment 77595


Where is the crack? I just rebuilt my S pump earlier this afternoon. Mine is the older clamp type as yours is the 8 bolt type housing. I used white lithium grease (brake lube) as it is not petroleum based which may attack the rubber components. And yes apply grease to the shaft bolt as well.
 
for $400 thats more interesting.

Honey! Guess what I want to Xmas? Poopy Potty Parts!!

I believe the whole pump assembly is close to $800. My rebuild parts were about $160. Does not include the motor as mine is fine. Once the motor is bad might as well replace the hole assembly.
 
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I tried JB Weld, but it didnt hold. Bought the new body.

I have everything back together, but its barely generating vacuum. What do I need to adjust? Really dont want to break something else.
 
Nr 10 on the picture I posted before is a common problem when less vacuum is generated.
But are you sure there are no vacu leaks anymore?
Does The pump stops?
 
Nr 10 on the picture I posted before is a common problem when less vacuum is generated.
But are you sure there are no vacu leaks anymore?
Does The pump stops?

I tried it on the bench and in the boat...small amount of vacuum generated. I pulled it and brought it home to adjust. So far new body, bellows (#10) and 4 duck bills.

Pump never stops running.
 

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