Beware New old stock

[alldodge]

Dated August 2015, bought 2 years ago (2018) so it was 3 years old when purchased

My Rinker
Removed the belt driven fuel pump and raw water pump assembly at the end of last season. Rebuilt the fuel pump side because found it started to leak last week.

I buy Merc brand new raw water pump kits (46-807151A14), which include impeller, pump housing, stainless plate, bolts, O and quad rings. There is no way I need the bolts but it comes in the kit

Just bought 2 new kits (Dated June 2019) this year for use in cruiser end next season

Now the issue; yes I know, will he just get to the point

Dropped boat in the water and did not make it to the slip before it was over heating. Tied up to closest dock and spent the next 2 hours finding out what happened. The new (NOS) impeller came apart in pieces

So I replaced the entire unit with a 2019 unit, finished the idle over to my slip

Findings during repair
When assembling first pump it was harder then normal to get the impeller in the housing. Also when pushing the impeller on the pump shaft that to needed more pressure to push it all the way on

Newer pump assembly impeller bent easier (not easy) and slide right on the shaft with not issues

The inside of the housing removed showed some burning but that was expected do to no water flow

If I ever find one that is harder to install in the pump again, it will get tossed in the trash

 

[nola mike]

Isn't the conventional wisdom that the impellers life is limited by age as much as use?

 

[alldodge]

Isn't the conventional wisdom that the impellers life is limited by age as much as use?

Agree, but as a DoD loggy, rubber is normally good for 20 years, other rubber items even longer

Don't know what material Merc uses, but if it gets brittle in 5 years that's bad. Could be its a one off, so will try to remember if its real hard going in, toss it

Many items bought don't even have a date code, at least Merc does

 

[Scott Danforth]

There may be a reason the VP is now recommending new impellers every 2-3 years.

my guess, the impeller rubber is now like the tire rubber business..... More fillers, less rubber

 

[zellerj]

I recently replaced a impellor on an alpha 1 and it lasted five minutes, and disinigrated on the muff during the test run. I attributed it to putting in an offbrand impellor (about half the cost of a OEM one). Replaced with a Quicksilver one and it was fine. The Quicksilver one did not have a date on the package or the impellor.

 

[dingbat]

Agree, but as a DoD loggy, rubber is normally good for 20 years, other rubber items even longer

Hardly anything is made of "rubber" anymore. Most impellers are Nitrile which is a synthetic rubber.

Nitrile is superior to most elastomers with regard to compression set, tear, and abrasion resistance but does not possess good resistance to ozone, sunlight, or weather.

Nitrile should not be stored near electric motors or other ozone generating equipment.

 

[alldodge]

Nitrile should not be stored near electric motors or other ozone generating equipment.

Mine are no where near anything like that, might have just got a bad one, stuff happens