Installing Fresh Water Flush Unit on Cummins 6BTA (NT32)

By Robert “Clay” Claycomb, Deneige, 32-276, Santa Barbara, California

Earlier this year, I decided to install a fresh water flush unit for my Cummins 6BTA. I saw that Seaboard Marine (located in Oxnard, California) described several different ways on how to install a fresh water flush in a diesel engine.  Seaboard also has a great YouTube video on this topic. 

After reviewing the different methods, I chose to buy the special Tee that Seaboard offers.   

When I bought the fresh water flush tee, Seaboard only offered the pricy Tee, now for the same price, it looks like it comes with a ball valve and fittings.   

I installed the flush unit in the Post strainer raw water hose. 

After buying the Tee fitting, I bought a 90 degree bronze male and female 3/4 inch fitting, a 3 inch bronze 3/4 threaded pipe, a bronze ball valve, a 3/4 inch male threaded to hose barb fitting, 10 feet of reinforced but clear 3/4 hose, and a Seafit male water inlet.  

The handle was shortened a bit and installed facing the other way to prevent snagging.

It literally took me less than two hours to install the flush unit.  I did buy special hose clamps from McMasters that do not cut into the Silicone hose.

To keep from dragging dirty dock hose through my boat, I chose to run a short hose piece out to the engine air intake vent where I attached a hose bib.  That way I simply attach the dock hose to the flush hose bib at the air intake vent.