Yanmar 3jh3e seawater pump - impeller

[Gary Ryan]

Thought I'd take a look at our impeller only to find I have a different system. Best I can tell is that my seawater pump is gear driven. Having said that, I'm hoping the plate to remove and inspect is at the front of our motor. See picture, bottom right silver plate with circle in it...below alternator. Is this the plate to remove/replace the impeller and o ring? I'm hoping it's not behind it.

 

[kloudie1]

That engine is notorious for the crappy access to the water pump. The pump is crammed back in there by the starter underneath the alternator. Some folks have been successful removing the impeller with long nose, 90 degree pliers after figiting the cover off. The water intake hose leads to where the impeller cover is. Check Harbor Freight for bent long nose needle nose pliers.

 

[sail sfbay]

Gear driven seawater pump. See diagrams below of the side of the engine aft and below the alternator (from the Yanmar 3JH3E operating manual) and standard sewater pump assembly and seawater pump impeller (from my Hunter 386 Yanmar 3JH4E service manual excerpt attached, which hopefully is the same on both engines). Suggest getting a service manual for your 3JH3E Yanmar Marine Diesel Engine 3JH3E 3JH3BE 3JH3CE 4JH3E 4JH3BE 4JH3CE Service Repair Manual Download (hqservicemanual.com) to compare. The attached 3JH4E seawater pump excerpt explains how to dissemble, inspect and reassemble. Without an access hole from the head, had to disconnect the transmission and forward motor mount, jack up the engine and rotate the alternator to get access to the seawater pump to replace it to a pinhole leak. Hopefully, you will not have to take such extreme measure to pull pump.

 

[Gary Ryan]

Thanks for the intel. That's what I was afraid of. You've got to be kidding.

 

[sail sfbay]

Gary Ryan, attached is the 3JH3E parts catalog and link to the water pump impeller kit and and gasket part numbers (note the part number differences so check with the supplier since the original part number may have been superseded): Yanmar Sea Water Pump For 3JH3E, 3JH4E, 4JH3E, 4JH3-TE, 4JH3-HTE, 4JH3-DTE, 4JH4E, 4JH4-HTE, 4JH4-TE (marinedieselparts.com)

 

[Gary Ryan]

Thanks for the information. Appreciate it!