Water Pump Impeller Design

[JJPage]

I have changed out several water pumps, on both 5. 9 trucks and 5. 9 standby Onan generators. I have noticed a difference in the impellers, some have an open vane design, and others have this funnel shaped disc welded over the vanes, looks like a turbo silencer ring inverted.



Most of the pumps I have replaced have the ring/disc, the new ones do not, new Cummins part #3286278.



My question is, what does this disc accomplish? Does it slow the flow? or just minimize cavitation? I guess where I am going with this... would the pump with the ring welded over the vanes be a better choice for our 3rd Gens? Not as likely to blow out freeze plugs would be my main goal?



If someone knows, please reply, also a Cummins part number for that particular water pump would be helpful. Jess

 

[steved]

The disc increases flow... its nothing new. Older cars used to have an "ac" and "non-ac" pump... the disc was the only difference for better cooling.

 

[JJPage]

OK, Thanks steved!



I guess I will try to replace mine, when the time comes, with a pump minus the ring.



What did "ac" / "non-ac" stand for? Is it the obvious, air conditioning?

 

[Shadrach]

The Cummins p/n for an 03 water pump is 4089142. Available as new only. Shadrach

 

[steved]

OK, Thanks steved!



I guess I will try to replace mine, when the time comes, with a pump minus the ring.



What did "ac" / "non-ac" stand for? Is it the obvious, air conditioning?

ac - air conditioning. At one time it made a difference... mainly because cars got hotter and they lost cooling capacity, so they had to "optimize" somewhere.



I don't think that either the one I removed, nor the one I replaced it with, had a closed impeller.

 

[JJPage]

The Cummins p/n for an 03 water pump is 4089142. Available as new only. Shadrach

ac - air conditioning. At one time it made a difference... mainly because cars got hotter and they lost cooling capacity, so they had to "optimize" somewhere.



I don't think that either the one I removed, nor the one I replaced it with, had a closed impeller.

Ok Guys, Thanks.



Shad I am going to take the number you provided vs the number I have, and ask the counter parts person at Cummins Northwest for an explanation. It seems to me they had several different #s for the same part, most likely superceding.....

 

[carl07230]

I just had to replace my water pump last month. Unfortunately it was on a weekend late at nite. Since it is my only vehicle i had to get what i could. I bought one from Auto zone and it has the funnel/cone or whatever on it-price $50. 00-$60. 00. Last week I was at the dealer and asked to see one of theirs. Stock one that came out did not have the cone on it and the dealers did not either. Their price for pump-$254. 00 plus tax.

 

[Shadrach]

Cummins has had way too many different p/ns for B water pumps over the years. Now they are finally superceding up a lot of the older ones. There are several different pulley designs and at least 2 different pulley diameters, which affect the speed at which it turns. One thing you can't see is the flow rate. I never could get a straight answer on the impeller ring. Shadrach