impeller service help

[deep denial]

am about to change impeller on a Nanni 4.38, with a new Johnson impeller from SPX. It helpfully provides a little tube of lubricant, and instructions which say 'lubricate the lip seal, but do not lubricate the mechanical seal'. I have no idea what they're talking about! What are these seals?

 

[Baddox]

When I’ve changed Nanni or Volvo impellers I’ve lubricated the rubber fins on the impeller so that it slides into the pump housing. Lubricating the fins will also give the impeller some protection against wear before the pump primes with water. Constricting the rubber fins using a cable tie makes it easier to push new the impeller back into place.

I guess the mechanical seal will be between the pump housing and the plate you need to remove to access the impeller. Check the outer rim of the pump housing and the mating face of the plate are clean, add the thin gasket without any sealant or lube and fasten back in place.

Use the tube of lubricant provided and not an oil based one which would damage the impeller.