2GM20F sea water pump

[Zeqoo]

After leaving about couple of month, tried to start the engine and heard strange sound from the engine room which was like slipping sound. And I found out the water pump pulley was not moving. Immediately stop the engine and checked the impeller but no damage but still the pulley on it was stuck. Tried to rotate the pulley by rattchet and it was heavy at first but anyhow moved. Few more rotating became smooth enough to rotate by hand and got smoother. Then applied marine grade lubricant and installed the water pump. Operated about 12 hours at 2000 to 2700 rpm seems no problem. I'm wondering the cause of this trouble because I found no foreign objects inside the pump nor pulley. Now do I better replace the water pump immediately or not?

[Juniper]

Bearings were siezed, if you have open seals the oil will work for a while, just keep oiling them, replace them at some point, standard bearings, get the double sealed ones, when you replace them, heat the bearings to ~150F and cool the shaft in the freezer they will slide right on.

[Zeqoo]

Thank you so much. I'll try that.