Impeller Replacement

[tborcher]

The installation instructions that accompany my new replacement Yanmar impeller state:
"Lubricate the lip seal with glycerin (do not lubricate mechanical seal)."
Pardon my mechanical ignorance, but what is the "lip seal" versus the "mechanical seal?"
Tom

 

[Brian B]

Apply the glycerin to the edges of the vanes. It helps to get the impeller in the housing and provides lubrication until it picks up water. I use a zip tie to compress the vanes and cut it off when the impeller is about 1/2 way in.