VacuFlush Hammers

[RumDiet]

My VacuFlush head has developed a hammereing noise when building up vacuum pressure. It starts softly then builds to a loud hammering noise. I replace all duck bills and tightened all fittings over the weekend. Any thoughts?

[Hud3]

Never had that happen with our VacuFlush, but checking for loose fasteners around the pump comes to mind. Have you watched the pump/tank assembly while it's flushing to see if anything is whacky?

[RumDiet]

Hud - Thanks for your quick reply - I had the whole pump out so I could replace the duck bills (impossible to get out without taking out the pump). Nothing looks whacky - but I can't see if what looks like a bellows has blown out. There was a slight bit of grease around the cam - but I assume that this is normal for a moving part.

[Hud3]

How old is the unit? It could be that he bellows have become stiff with age or encrusted with mineral deposits on the wet side. Since the bellows pump back and forth, it would be a likely suspect for the noise.

[RumDiet]

The unit is a 2005. Can I replace the bellows - or does this mean the entire pump has to be replaced?

Are there any schematics out there - the owner's manual is a joke!

[Hud3]

I had a tech service my VacuFlush due to weak vacuum, and he removed the bellows. It was encrusted with mineral deposits, even though we used fresh water for flushing. He knocked off the deposits and put it back in. All worked fine after that and a few other adjustments and tweaking.

Replacement parts for the unit are available online, usually in "kits" of various prices. Here's one site that came up in a Google search: Rebuild Kits, Ecovac, Vacuflush Rebuild Kits

[RumDiet]

OK Thanks - its off to see my friend the plummer! I never have trouble taking stuff apart - its always putting it back together that gets me in trouble! COme to think of it - maybe this is a winter project!

[pushybroad]

Most likely a bellows issue. I am a certified Vacuflush tech and suspect as others have said its the bellows. The cost of the bellows depends on your model but last time I bought those alone it was around $90.

If you have not had much need to service the Vacuflush you may just want to bite the bullet and buy the rebuild kit. These heads are pretty bomb proof and once rebuilt it will be likely headache free for a very long time. Good way to get rid of a head=ache ;-)

Good luck!

Lori Wallerstein
ABYC Marine Systems Tech
Vacuflush Tech

[RumDiet]

Lori - thanks for your input - I think I am leaning towards replacing the bellows and see what happens - are there any other parts that I will need (ie. gaskets, seals, tiny weeny parts that are likely to get lost?)

Do I have to separate the upper and lower portions of the pump? Seems like there should be something like a gasket in there to be replaced.

Any part numbers would be appreciated.

Thanks again

[HopCar]

Lori, I'm not familiar with the top end of those pumps but the op said "There was a slight bit of grease around the cam", is he talking about the thing that turns the rotary motion of the motor into an up and down motion of the piston rod? If so it is similar to the old style PAR diaphram pumps. They would start to knock and leak grease when that part got worn. The knocking would get louder as they built pressure. That kind of sounds like what's happening to the OP's vacuum pump.

[HopCar]

I finally found a drawing of the pump. My guess is the bushing that the bolt connected to the excentric runs through is worn. A new bushing comes with the bellows so yup, a new bellows would fix it. Unless the bolt is worn.
Here is where I found the exploded drawing: http://www.dometic.com/FileOrganizer.../VacuFlush.pdf

[RumDiet]

Ah - THANKS ever so much - that's just what I was looking for!