water pump impeller musings

[fairdeal]

replaced the impeller on the F225txrd last month - was performing fine, but had been in use for 27 months, about 600 hours

the removed impeller looked great - never suck up sand, or run it dry - so the rubber surfaces were pristine

but it had acquired substantial "set"



Yesterday I happened across a lightly-used impeller from my Mercury (the powerhead is Yamaha, but the LU is Merc)

Was reminded that, in contrast to the Yamaha, there is "no up or down" to the Mercury impeller keyway



Raises interesting questions

are all Yamaha impellers "directional" - an "up" and "down" side of the keyway? and why?

and with a non-directional Merc impeller - if that was removed with a "set" - but otherwise in excellent condition -

why not re-install it going the other way - to compensate for the set?

[99yam40]

I would be afraid of the rubber cracking and falling apart.
I have seen some loose pieces and one that came loose from the plastic inside that fits over the shaft and key.
stuff that have been in use for too long is my guess

[robert graham]

I replace my impeller every 3 years and it always has a "set" in the vanes/blades....very little wear or deterioration.....every 3 years and no problem...just one less thing to worry about!

[pstephens46]

I don't know about flipping and reusing. I replaced the impeller the first year of F150 ownership.
The impeller was installed upside down based on the key way. They just smashed it through the closed area. It was working fine but replaced anyway due to lack of records.

[zenoahphobic]

Setting of the impeller will always happen.
Happens to me when I try to get up after falling asleep in front of the TV. Try cutting the ends of the impeller blades so they don't bend if it bothers you😊Probably still work at speed as a centrifugal pump.

[HenryTolliver]

I replace my impeller every 3 years and it always has a "set" in the vanes/blades....very little wear or deterioration.....every 3 years and no problem...just one less thing to worry about!

Hmm, thanks for the tip!