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Prime raw water pump

J

jasonious

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"Hi All,

First time cleanin

"Hi All,

First time cleaning my raw water strainers yesterday. I closed the seacocks, opened the strainers and cleaned them out. First time I attempted to put the strainer together, I had a leak so I closed the seacock and did it again. Now, when I throw the seacock open, no water fills the strainer. If I turn the motor over a couple of times, the strainer starts to fill. I don't want to run the impeller dry, so what do I do? Is there a trick to prime the pump?

Is this normal behavior?

Thanks!"
 
"not real familiar with the st

"not real familiar with the strainers but sounds like the height of the water line is lower that the strainer so it wont fill, when you turn the motor over it sucks the water in.I would fill the strainer with water put it back together,then fill your system at the raw water pumptill its full that would be primed.fire it up and watch the exhaust"
 
"Here's what I would do...

"Here's what I would do...Shut your sea cock, fill your strainer, add some dish soap to the water,re-tighten every thing, then open the sea cock & fire the motor, the dish soap will provide a little extra lube for the pump, plus you'll see the bubbles before the water flow from the exhaust so you'll know your pumping"
 
Thanks for the replies. Troubl

Thanks for the replies. Trouble is my strainers lie horizontal to the hull. No way to fill them before assembling without the water pouring out.

Jason
 
then put em back together open

then put em back together open seacock and fill from the raw water pump till u cant fill no more
 
"How about pulling the hose fr

"How about pulling the hose from the water pump,and then cracking the sea cock to 're-prime' the system. Once water makes its way toward the pulled hose end, pour some liquid soap into the pump (so it's not a dry start), then reattach the hose.

Sounds like it just needs repriming."
 
I have a setup like that. In

I have a setup like that. In the Spring (can it get here fast enough!) I stick a water hose up the pipe from the strainer when I fire it up. One of those turn to adjust nozzles works slick.

Jeff
 
Dewinterizing Chrysler 318.

Turning over engine for first time of season...smell the rubber burning smell.

Guess I took some life off my new (last season) raw water pump. Finally got the strainer bowl to seal for a good airless water run. The new bowl seals are a pain in my *&^. They are round o ring seals that slip when I tighten the bowl cap on....after I work with it for a bit I can get it to seal...wish I had the original "flat" seals....still looking. :mad:

After running my raw pump dry :rolleyes:...next year I plan on..putting a little dish washing liquid in strainer bowl hose (for lubrication), then spraying water in with nozzle from garden hose while cranking over engine. Got the idea from another thread....thanks:cool:

May not hurt to run the pump dry for a bit...not sure. I think it would cause premature failure.

What do you guys do?? Run it dry or lub it??
 
There is a very simple solution to this if these are Sherwood belt driven sea water pumps!

Remove the outlet side hose from the pump (the upper port supplying the engine).
Add Glycerin from a drug store directly into the outlet port. (dish soap works also)
Loosen the drive belt, and turn the pump over by hand in the normal driection of rotation (or bump the starter motor).
This will spread the Glycerin around the impeller vanes and within the pump body.
It will allow for the pump to operate far long enough to pull sea water into the system.
If it doesn't, you may have a suction breach somewhere.

Your impeller will be unscraved during several quick start-ups.

.
 
Not sure why all that is necessary UNLESS you're one of those folks who don't pump the Pink Stuff through your motor until it comes out the back. When you only pour it in the t-stat housing (and hope for the best) the impeller is sitting there in old, cruddy water. With the Pink Stuff inside the housing,the impeller does not stick in the spring (and ice can't crack the housing).

Jeff
 
I do use the pink stuff through the filter bowl trick.

I like the sound of blowing bubbles (dish liquid) from the back of my RIG :rolleyes::rolleyes: Can't wait !!!

May rename it "BUBBLES" ;)
 
Last edited:
fastjeff said:
I never, ever run the motor without lots of water at the pump.

Jeff
Click to expand...



After putting in new impellers and tune up work, I plan on starting both motors on the hard too make sure I didn't screw anything up. To do this I'm gonna take the belt off of the raw water pumps then start them for about 10 seconds. But I do have fresh water cooled motors so the antifreeze will protect both motors..
 
hey everyone i have a crysler 318 inboard that im having a over heating problem with.. i get the boat in the water start it up and rev it up a few times to prime the water pump, we go out for for a lil bit and it stays cool for about 20min then starts rising then going back down and rises and goes back down then it shoots up to 200... take the hoses off and no water just steam... it does have a new water pump... anyone got any good advice for me????:confused:
 
I'm betting you have an air leak before the raw water pump. Doesn't take much of a leak to cause what you described.

Jeff
 
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