AC raw water pump

Any suggestions on pumps? My March
AC-3CP-MD gave up today. Got power to it. Plenty of screened Water going to it, but no output. Should I just buy another March pump, or are there better options? I have no idea how old this one is. It was on the boat when I bought it. Thanks, Don

If the motor runs it maybe an o-ring is leaking and the pump drawing air. Make sure the pump body is flooded. If you're not using an intake strainer, you could have a plug. You can but a wet end kit for about 1/3 of the whole pump.

March and Cal are the two I am familiar with and between the two, the March gets better reports.


David

A March pump came with ours and was running hot and making bad noises. A close look showed there’s two oiling ports. Now I oil those twice a year and all is well. I did have a spindle break after acid washing sent something crunchy into the pump. $10 from Depco and we were back in business. I do carry a new in the box spare but don’t think I’ll be needing it for a while.

When I checked the pump right after it quit the motor was hot. I bought it home , hooked it up and it started right up and pumped a strong flow of water. I’m going to let it run for awhile and see if it quits again. Im going to replace it regardless, since it’s done this once before.

Try oiling the motor. Worked for me but I still carry a spare.

Speaking of Depco, give them a call tomorrow and discuss your situation. They will have some expert troubleshooting advice and get you the right pump, if you really need one, or the right parts, or refurbish yours.

However, it sounds to me like you have an upstream airlock in your system, usually caused by a sagging hose preventing you from having a continuous uphill route to the compressor system. You certainly have the symptoms.

March makes very good pumps, though I'm an Oberdorfer man myself, and I certainly wouldn't switch out a March just for the sake of it.

I have had good luck with March pumps.

March pumps seem to be very reliable and last years. I just had to replace one this year as well. I installed it 7 years ago. It had power but was not pumping. The other pump on the boat was there when I bought the boat 7 years ago. It's still pumping fine.

I disassembled it. The magnet drive shaft was eccentric, that is, it wobbled. It caused the driven magnet surround to rub and eventually seize on the exterior shroud. Looked like a factory defect to me. I cleaned it up, sanded some of the burrs off the surfaces, greased them, and put it back together. It's now a spare on the boat.

The motors are sealed. Have no idea how you can oil them?

I recently went through this for an ac genset pump
March are a US thing so prohibitively expensive here so I purchased a resun/iwaki md30.
Very solidly built, heavy and rated for continuous use of saltwater.