water pump reconditioning

[rebars1]

I am restoring a 1959 35hp Johnson RDS-20 and when I pulled the water pump off I noticed that a portion of one of the impeller fins was missing and that there was some minor mineral deposits in the pump housing. My questions are: 1) where did the missing piece go? Do they usually pass through or do they get stuck inside somewhere?, and, 2) Can I smooth out the inside of the pump housing with fine emery cloth (say, 800 grit) or should I order a new housing?

 

[walleyehed]

Re: water pump reconditioning

The mineral deposites can be cleaned with a small amount of muratic acid. If it's grooved, replace housing if it's available.<br />The missing blade just about had to go up the tube and into the block if it made it that far...it could be blocking a thermostat, it could be stuck in a cylinder passage. Very small pieces may go through but you never know how big the piece was or even if it went all at one time...

 

[rebars1]

Re: water pump reconditioning

Thanks, walleyehead. The piece that's missing is about one third of the length of the fin and is a clean break. No way to know if it got ground up before leaving the pump housing. I also have no idea how old the impeller is (atleast 16 years, but not used at all for the last 10 or so). I'll check the thermostat and water tubes as best I can for pieces.