Ac cooling water pump

[Kquaine]

What is the best way to prime the ac cooling water pumps? The salon/mid berth cooling pump is making a loud vibrating noise. I’m betting air is trapped because it was recently on the hard for 5 months and it lost prime.

 

[Captain Ralph]

When installed correctly, AC pumps do not need priming.
However, sometimes this just can not happen.

Some Bronze pumps have a bleeding screw or bolt on the top. You can open this. Ensure the sea-cock is open, Watch out for that plug and not let it loose when the water starts to flow.
Or try to loosen the out hose from the top of the pump till steady water comes out, re-tighten.

Once the pump has a good belly of water with no more air coming to it, it will push the rest of the lines clear (pending any restrictions).

 

[Sadey]

For whatever reason one of my A/C Grocos requires bleeding. They are within 6 inches of each other but one is finicky. Side note: So far Benedetto has caught 5 fish without a single fishing pole on the boat. One of the engine strainers caught 4 and one of the AC strainers caught the other one.

 

[Pascal]

99% of the time the reason for air con pumps too lose prime is when there is a high spot in the hose between the strainer and the pump inlet. Eliminate the high apot and the problem goes away

 

[Sadey]

That strainer is slightly higher on the hull than the other strainer and maybe it’s slightly higher than the pump.

 

[Pascal]

That could be the problem. Any high point will cause an air lock

 

[firbanks]

Had to do this a couple times with March pumps after strainer clean out before I re-mounted my strainers vertically. Easiest way I’ve found is with the strainer back together and the seacock open and AC OFF, take the bucket head / wet vac into the generator room and pull one of the flex hoses off the condenser and suck seawater through the hose. Until you have water in the bucket. Stick the line back onto the condenser and snug up both hose clamps. Turn on the AC and that’s always worked for me.

 

[jmooney]

I installed a small stainless steel ball valve at the outlet of my March A/C pumps . This lets me bleed the air out of the system after cleaning the strainers . Much easier than taking a hose loose .

 

[carolinacoast]

Here is our setup. No ac priming issues. Plumbed as Pascal suggests. 2 pumps, 2 strainers. 1 thruhull is not ideal, but has been ok for years.
Have a manifold above for the pressure side of either pump, and a control box for both pumps and extra triacs inside.

 

[Kquaine]

Good news. Found the pump. It just needed to be primed. The boat has sat on the hard for 5 months with the seacock open.

Thanks Everyone

 

[Doug.T]

What is the best way to prime the ac cooling water pumps? The salon/mid berth cooling pump is making a loud vibrating noise. I’m betting air is trapped because it was recently on the hard for 5 months and it lost prime.

On my 1986 53MY the suction strainer is higher than the pump. I take the cover off the strainer and
open the thru-hull until the basket fills and overflows into the pump.