How to Make an RV Macerator Pump

I needed a way to empty my RV tanks at home.   The RV port is 125 feet from my septic tank and 24 inches below the septic tank. 

Initially, I purchased a Flow Jet pump.  It was a hassle as I had to unhook it inside the compartment (would not fit through the hole in the bottom of the compartment.  Always left a bit of a mess.  I could not leave it attached permanently due to compartment size restrictions.  I took it with me for a few trips and used the FlowJet instead of the 3" slinky.  I liked it, and decided I could live with a pump.  Now...... how to make it fit?????

I work in the marine industry and the ShureFlo marine macerator pump is very well respected (it is rated to grind up fish guts or sewage all day long).  And.... you can buy them at any marine store for a quick replacement.  Now the challenge, hooking a marine ShureFlo pump to the 3" bayonet sewer fitting AND fitting it inside the compartment.  Actually, it is pretty easy.  Cost: $114 for the pump at Amazon.   $9.97 for the Valterra fitting.  $2.27 for the 1 1/2 to 2 inch PVC fitting at Home Depot.

I realize you can purchase a complete macerator kit for about $200.  But, this one has several advantages.  1.  It is much shorter in length.  2. The pump is really high quality.  3.  You can purchase a replacement on the road just about anywhere there is a marine dealer or West Supply.  4. It is much cleaner when you unhook as it does not have that long snout that holds crap.  5. It is noticeably faster.  The ShureFlo has a 1" outlet.  Will work with a garden hose but 1" bilge tubing is much faster. 

I no longer use a long hose for the whole distance.  I have buried a 1" PVC pipe that comes up on one of the posts in the RV port.  Works great. 

Time to do the project: 20 minutes.

Feel free to email me if you have questions: max@strother.cc

Click on pictures to enlarge

Step One: Get the pump and cut the hose connection off at the pipe threads.  ShureFlo pumps are able to be attached with a hose and clamps or with a 1 1/2 pipe thread.  Use the thread and cut off the hose nose with a hacksaw. 

Step Two - Make the Bayonet Fitting Adaptation.  I used a standard Valterra hose fitting.  Cut off the hose part.  The key is to leave the fitting just long enough to insert the PVC pipe adaptor fully. 

Step Three -- Had to remove a bit of a molding flashing ring in the red connector to make room for the pipe.  Could easily be done with a file but I had an air tool.  Valterra fitting is tapered and PVC fitting was too tight.  See step 4.

Step Four - Have to slim down the PVC pipe adaptor to fit into the red Valterra fitting.  A file would work but angle grinder makes quick work.  Do not need to remove much.  Valterra fitting slims down a bit.   Easier to take it off the PVC fitting OD than the ID of the Valterra fitting. 

Step Five -- Glue it up.  Use West Brand GFlex Expoxy.  If you to not have Gflex, get some.  It is great stuff for a lot of repair.  Works well with plastic if you follow the instructions and flame the plastic before gluing.   Unused portion will last forever. 

Step Six -- Finished Product

Step Seven -- Screw pump into fitting.  Use pipe dope -- will make it easier to replace pump down the road.  I use Teflon PVC threaded pipe dope.

Fits with room to spare!!!  Hose is 1" bilge hose.  Smooth on inside. Connectors are Banjo connectors.  White ball valve is not necessary.  I thought I would need it but do not.