Raw Water Pump - No Suck

More
11 years 1 month ago #200 by Roy Belcher
Raw Water Pump - No Suck was created by Roy Belcher
While starting to winterize I put the intake hose from my raw water pump into a bucket of fresh water with a garden hose at the ready to refill as the bucket emptied. It worked fine for about 10 minutes, but then stopped sucking. I quickly put the garden hose directly into the raw water intake hose, and continued till the engine had warmed up. I then shut it down and filled the bucket with antifreeze, and restarted the engine. NO SUCK!

I changed the impellor, blew through the heat exchangers to see that there was no blockage, removed the flow alarm from the intake line and refilled the system with fresh water. Still NO SUCK when I restarted the engine.

Today, I removed the old (Johnson) raw water pump and replaced it with my spare brand new Johnson pump. (It took most of the day)

Tomorrow I'll restart the engine and hope it sucks up the antifreeze, but I'm puzzled. What could cause the Johnson pump to stop sucking? There was some corrosion on the inside of the impellor housing.

Roy B.
Serenade W-42#45

Please Log in or Create an account to join the conversation.

More
11 years 4 weeks ago #204 by Greg Temple
Replied by Greg Temple on topic Re:Raw Water Pump - No Suck
Roy, Did that fix it?

One other wearable item is in the pump chamber besides the impeller. It is a "constrictor" for want of a better term - I'm sure there is one - that serves to restrict the chamber volume and compress the impeller blades. This is the "hump" that compress the impeller blades. These have been known to wear out In in the pumps I'm familiar with, are retained by a screw to the inside wall of the pump chamber. It is possible it was scored by previous attempts to remove the impeller. If this becomes too worn, the pump will not work. I've never had a pump fail due to this, but if the pump shaft turns, the pump is primed and the impeller is OK, the pump has to pump.

Please Log in or Create an account to join the conversation.

More
11 years 3 weeks ago #226 by Roy Belcher
Replied by Roy Belcher on topic Re:Raw Water Pump - No Suck
I'm happy to report the new Johnson raw water pump sucks the bucket dry, even with the garden hose running.
Closer examination of the old pump reveals some pitting and wear on the interior of the pump chamber. Thanks for the explanation.
Roy B.

Please Log in or Create an account to join the conversation.

Time to create page: 0.108 seconds
Powered by Kunena Forum