Macerator Pump Replacement???

[SilverLining]

Am tired of pulling the internal GROCO macerator pump in my Sailfish 272(2000). In the past, I have replaced the ceramic seals, bellows, etc. Seems that I have to remove and free up the pump every six months or so. Probably need to put a zipper on it.

Has anyone replaced the internal pump with an external pump? The electric head has an internal macerator prior to the holding tank. Seems that I could modify the existing pump mounting/sealing plate or build a blank with a dip tube from inside the tank to an external pump. Any thoughts or suggestions???

 

[BobP]

I presume you pump overboard, if so, you need an external macerator with a 1.5 inch outlet port from holding tank. The electric head macerator doesn't help you clear out the holding tank.

 

[SilverLining]

Thanks BobP. Understand that the macerator in the head does not facilitate pumping overboard, however that means that the liquid in the tank has been macerated. My question concerns the installation of a dip tube in the top of the tank extending down to about 1/2" off the bottom(using the old internal pump mounting plate) and installing a remote(macerator) pump to that dip tube for over board discharge through the existing hoses and thru hull. Anyone see any problems with that setup???

 

[BobP]

No problem, as long as you seal the tube at the tank top, don't know if top has a treaded insert. You can make up a tube form what's on the shelves at the depot as long as there's something to thread into. Polyethylene doesn't bond well.

Alternately, you can order a new tank, on tanks.com, plenty of of size selection, fast delivery, and then specify where and how many threaded female fittings you want - if the standard fittings don't cover it. Reasonable prices too.

My tank fitting (3) are all on one end on the side and it works fine pumping out from the lower side. I bought a standard tank at a very good sale price, but they will put the fittings in the top if preferred. You'll have to do your own draw out tube design which is simple enough.

 

[BobP]

Dometic Sannipotti and Vacuflush use a non-threaded dip tube fitting in their tanks which is comprised of a thick rubber or vinyl gromet about the penetration and snug friction sealed tube, no threads.

Don't know if such part kits are available for DIYers. I looked in the past and didn't find anything.

 

[JOSH S]

When the internal pump went out on ours this summer, I decided there was no way I'd ever pay 4-500 dollars for the inferior designed internal macerator pump. I reused the top plate and fabbed up a pickup tube out of pvc and sealed it up. I purchased a 125 dollar external macerator pump and plumbed it inline and it works like a charm every time. It is also much easier to get to for service also. Total costs was about 150 dollars and about 2 hours of my time.

 

[Grog]

When the internal pump went out on ours this summer, I decided there was no way I'd ever pay 4-500 dollars for the inferior designed internal macerator pump. I reused the top plate and fabbed up a pickup tube out of pvc and sealed it up. I purchased a 125 dollar external macerator pump and plumbed it inline and it works like a charm every time. It is also much easier to get to for service also. Total costs was about 150 dollars and about 2 hours of my time.

Ditto, except I used a 1/4" Aluminum plate instead of the original cover. The original pump is a horrible design (unless you're the supplier)

 

[SilverLining]

Thanks Josh S & Grog......what size(ID) tube did you install throuigh the cover plate. Did you go with a 1.5"ID to fit to the new pump or did you reduce it down to a 1" or less???

 

[Grog]

I think 1 1/2, it's the same diameter as the pump inlet. You want that hose to be as big as possible so none of the nasty clogs it. The only change was the outlet hose, the old hose was 3/4" and the new is 1".

 

[1st grady]

How about this one? It seems like I have this project as well. Aluminum plate bent at a 90 degree to attach the pump and a 1 1/2 inch hole in the one leg of the angle to attach the inlet tube.

Lay the pump horizontally and use PVC elbows?

How does this seal at the top of the tank?

 

[Grog]

That's basically the same pump I used. I T'd into the pump into the pump-out line and sealed the round hole with the 1/4" Aluminum mounting plate. As long as the seal on the pump-out cap is tight there isn't a problem. The trick was to keep the whole new system similar in hight as the old since it's under the aft bunk.

 

[JOSH S]

I had to relocate my pump. I used that same type of pump also. I can't remember exactly but I know the new pump is not on the tank itself due to interference with the access panel. I believe the pump is at the forward side of the tank. I used an elbow and short piece of hose from the tank to the pump. Then from the pump the hose goes to the seacock.

 

[SilverLining]

First thought of using a 1.5" dip tube into the tank to fit the inlet of the new pump. Hose run is to be about 14". Ever tried to bend 14" of 1.5" sanitary hose???? Not good.

Realizing that the liquid in the holding tank has been macerated by the electric head, had little concern about reducing the suction side of the new macerator pump to 1".

Removed the internal pump from the plastic plate and fitted a 1" ID PVC dip tube through the plate down to about 3/8 - 1/2" off the bottom of the tank. With an elbow on the top of the dip tube fitted 1" ID sanitary hose from the elbow to the 1.5 " inlet to a Jabsco macerator pump located to the port side of the holding tank. Used existing discharge hose to through hull. First trials are O.K.