It Just Won't Suck- Antifreeze

[slocum2]

I'm scratching my head over this, any constructive thoughts are appreciated.

Winterizing my 20 HP Universal Diesel I filled the bucket with anti-freeze, disconnected the intake hose aft of the sea-strainer (more room) but the engine wouldn't suck-up the antifreeze. It turned over but the antifreeze in the bucket didn't move. I thought it might be the impeller (although I had no real reason to think so since it had been pumping fine all summer) and changed the impeller. No difference.

Why wont it suck up the anti-freeze???

[xort]

Try priming the hose to the pump. You may have to hold the hose up high and poor antifreeze in or else get a small electric pump to push the antifreeze in

[groundhog]

Symptoms of an old pump...?

When you changed your impeller, did you see some wear on the bronze inside? Looks like little ridges on the flat sides of the cavity. Or like someone lightly milled down the lid where the impeller rubs by like .020-.030"?

There is a little raised area on the curved side of the cavity. Sometimes a screwed in plate. This can get worn down over time. THis is the thing that makes the pump pump.

These pumps should be self-priming I think. Mine is.

When these things wear out, they basically leak inside themselves and get weak.

groundhog

[k1vsk]

or try buying it dinner

[groundhog]

Also those strainers only go one way.
Make sure you have the in/out correct or you won't get anything to move.
gh

[Maine Sail]

Sometimes they won't prime at low RPM when dry. Simply rev it up and she should start sucking. Once she does back her down. If it does not begin to suck in a few seconds at a higher RPM shut it down and lube the impeller with glycerin or mineral oil and repeat.

Before doing all this make sure the strainer is full by holding the hose at the level of the siphon break and filling it with antifreeze via a turkey baster..

P.S. My 44hp can suck a 5 gallon bucket dry in 50 seconds at 1200 RPM at 2000 RPM it drinks it much faster. The flow rate is dependent on the engines RPM. Low RPM passes less water and higher RPM pass more..

[Quickstep192]

I rigged up a bucket with a thru-hull fitting in the bottom so I can get the antifreeze source above the pump so it doesn't have to self prime. Mine connects into a flushing fitting, but could just as easily go right to the intake hose. It looks like this:

[Maine Sail]

Please, please, please be very careful!!!!

Some words of caution:
#1 If your bucket is located higher than your engines siphon-break, NEVER, DON'T & DO NOT shut the engine off without pulling the intake/sea strainer hose from the bucket and letting it suck dry or down bellow the level of the siphon break!!

I always pull the hose and let the impeller suck the remaining water from the hose before shutting down the engine.

Why?

If your bucket is above the engines siphon break your engine can, and will, fill with water and you will hydro-lock it. This is NOT good and will require many, many oil changes to get rid of all the water in the engine. It may not happen the first time but it will and can eventually happen.

Please do yourself a favor and remove the hose from the bucket before you shut down!!! Raw water pumps are NOT valves, are NOT a positive shut off and they do not stop gravity or siphoning. If your bucket is above the engines siphon break it will siphon and you can and will eventually have a hydro-lock situation where your cylinders fill with water.

If you do this in the cockpit, as most of us do, there is a very high likely hood that your engines siphon break is bellow the siphoning level of the bucket.. Pleas be careful.

#2 Never, ever connect a hose straight to your engine. The street pressure will not only blow out the seals of the water pump but within in seconds, even running, it can hydro-lock an engine. Municipal water supplies can have street pressures as high as 100 psi. Use an in/out bucket to avoid serious damage!



In/Out Bucket (Mini Simulated Ocean):


Hose from In/Out Bucket To Sea Strainer:

This is an engine siphon break. If your in/out bucket is higher than the siphon break it can not break or stop the siphoning!!!! Pull the hose before shut down!!!

[slocum2]

Thank you for all the responses. The boat is out of the water now. I didn't have this problem last year, drank it all down in a minute or so.

If I don't get totally rained out tomorrow I'll let you now how it worked out

[sailingdog]

Maine Sail-

Which of the Oceans is that: