Replacing impellers

[oldgit]

..on a related note: should I be concerned by the different Impellors, some with a rubber end cap and some without? Both apparently VP parts for the belt-driven pump on my MD22p.

Sometimes fit them and sometimes do not.
Have yet to find they make any difference at all to the ease or difficulty of removing the impellor at a later date.

 

[ChromeDome]

Interweb searching finds:

• Neoprene offers a wide range of chemical resistant properties and a temperature range of 45-180°F (5-82°C).
• 
  
• Nitrile impellers are recommended for a wide range of oils, oil and water emulsions, diesel fuel, hydrocarbons, and lubricating oils.
• Nitrile has a temperature range of 50-180°F (10-82°C).
• 
  
• EPDM impellers are resistant to weathering, ozone, and many chemicals, and can withstand temperatures up to 185°F (85°C).

None of them are unsuitable for water, so unless you have special needs, the material is unlikely to be crucial.

Most common names are Jabsco and Johnson pumps, with quite a few impellers being interchangeable between them.
They make private label series for certain engine manufacturers.

Jabsco, owned by US based Xylem (was ITT before 2011), seems to be the leading brand in marine applications.
Johnson, originally from Sweden, was acquired by SPX Flow who these days is owned by the US equity firm Lone Star.

The contents of impeller kits are not always the same; some have more parts than others. Incidentally, the included lubricant that protects the impeller during the first time dry run until the water reaches it, usually is based on silicone or glycerine.

For lack of a better almost any lubricant can be used.

 

[Montemar]

Put a Ty-wrap around the impeller and pull tight to pull in the vanes. This will let you get it started. Tap in until over half in, cut and remove the Ty-wrap then tap home. Use lubricant if you want.

 

[Rickard]

I was just reading , on the sealine forum, and the guy says he plasters the impeller and the strainer with fairy . He says it helps with the impeller does not stick , also you see the bubbles coming out at the rear so you know it’s pumping . It maybe an old tip.

It works very well. I also use when removing the impellers. They come out very easy and no special puller ever needed

 

[stuartwineberg]

I always liberally smear silicon grease on the metal pin that goes across the impeller as that can bind on the pump shaft.