I had a pair of Turbo 395. I bought aftermarket pumps cause Cummins has no imagination to increase volume without increase pressure. The impeller is cast but the aftermarket one is bronze
with very sharp progressive veins. Push more volume and balanced for its bearing and housing.
They are tricky special tool just for that version of a pump
casting. Then the parts
are pressed together with a hydraulic press.
It’s been popular to replace Yanmars pumps with electric
and I can’t tell you why but it’s not a great idea. It’s an average pump depending on what year or maker of the block. Some have a weep hole most don’t do rule
of thumb is 1500-2000 hours. $125.00 rebuilt exchange.
An out board needs an impeller annually $27.00 Average. Yanmar
need a pump every 8 years average. Winterizing, dirty bilge
, poor oil
changing habits and so on anyone’s guess. Maintaining hoses debris in heat exchanger
maintain fluid levels all play on the pumps life span. The antifreeze
has lubricant in it which expires. Detergents which no longer clean. Like oil
they need careful changing
Hope this helps