Nitrile vs. Neoprene Impeller

[SkiprJohn]

Is the extra cost of nitrile worth the expense? Does it last longer?

JohnL

[delmarrey]

Originally Posted by SkiprJohn

Is the extra cost of nitrile worth the expense? Does it last longer?

JohnL

Not unless you plan on running something besides water through your pump. Nitrile is for petro and chem's.

There are three reasons most people have to change an impeller.

1) It gets old and breaks up.
2) Someone forgets to open a valve and it burns up.
3) A line gets plugged and burns up.

And I believe #2 is most common! So it wouldn't make much difference in longevity.

BTW if the impeller burns up, most people forget to change the shaft seal when they install a new impeller which actually calls for a disassembly. When the impeller gets hot so does the shaft and usually cooks the shaft seal. It may not leak at first but it doesn't take long for that hard rubber to cut into the SS shaft. And when it leaks it takes out the bearings.

I carry an extra shaft, bearings, seal and impeller just for Murphy.

[SkiprJohn]

Thanks Del. I've got the idea of having a spare reconditioned (by me) pump aboard. I really have to take one apart to see what's in there. I ordered a couple of spare impellers from Fisheries and they seem to know only about the nitrile and didn't know the numbers for the neoprene.

Once I know the difference between a lip seal and a face seal then I can order the right parts to do a new seal on my older than dirt pump. You've helped me on this one in the past and I just need to see the seal to get an idea of what it is supposed to look like.

Regards,

JohnL

[Stevek]

John,
I recently rebuild a Johnson water pump">raw water pump. After disassembling it, I took the seal and bearings to my local bearing supply store. They had everything and at about a third the price of ordering though a Marine store. Well worth the effort. ( By the way, the seal was pretty mangled but the sales clerk knew instantly what it was. I guess they are pretty standard)

Steve K

[delmarrey]

Originally Posted by SkiprJohn

Thanks Del. I've got the idea of having a spare reconditioned (by me) pump aboard. I really have to take one apart to see what's in there. I ordered a couple of spare impellers from Fisheries and they seem to know only about the nitrile and didn't know the numbers for the neoprene.

Once I know the difference between a lip seal and a face seal then I can order the right parts to do a new seal on my older than dirt pump. You've helped me on this one in the past and I just need to see the seal to get an idea of what it is supposed to look like.

Regards,

JohnL

I heard it said that for some pumps they only sell the nitrile. I should have mentioned that eariler.

The pumps are EZ to take a part. There's a snap ring on the front. You pull that and push on the impeller end and the shaft will come out with the bear(s) on it. The lip/face seal will remain in the pump. If you can shoot a good picture of that and post it we'll know.

But it shouldn't be too hard to figure out. The face seal will seat against a disk/face perpendicular to the shaft. Part # 11 in the picture (#'s on parts don't match the parts list-error)

http://www.cruisersforum.com/forums/62437-post5.html

A lip seal will seal right on the shaft.

[delmarrey]

Now that I'm home and on a real computer I'll shoot you a couple pictures here. The first one is a standard lip seal the second is a different pair of face seals. The real difference is the lip seal mounts in the housing. The face seal mounts on the shaft. So, when you pull it apart you'll know by how its mounted......................_/)

[SkiprJohn]

Aloha Del,

That is great information and really clears it up. I can't thank you enough.

Kind Regards,

JohnL

[SkiprJohn]

Aloha SteveK,
Thanks to your advice I'm going to try our local bearing shop once I get the pump apart. How's your Cascade?
JohnL

[austinrick]

For the aftermarket freshwater Jabsco pump add-on on my Yanmar 2GM, is the antifreeze in the system detrimental to a neoprene impeller? I assume neoprene is okay on the raw water side.