Clampett

Will it work? I had this discussion with a buddy and now my water pump is leaking. The 6.7 has 7 blade impeller where the 5.9 has 5 blades. Anyone use a 6.7 on their 5.9 yet? I just called my local Cummins dealer and that guy knew nothing about their compatibility. I'm guessing the 6.7 flows more water and in return would keep the engine cooler. Thoughts?

Flake

No idea if it will fit, however it is possible to move coolant too fast, if it doesn't stay in the radiator long enough it can over heat.

In high performance after market muscle car stuff the make flow reducers to slow the coolant flow after you put on the high flow waterpump. It fixes a problem the builder created themselves.

Angry Johnny

I have heard this forever yet I've never seen a case where the coolant flows too fast. Those reducers were supposed to take the place of the restriction the thermostat created when the t/stat was removed in order to cool the engine down between rounds at the drag strip. The logic was if the coolant didn't stay in the engine long enough it wouldn't transfer as much heat to the coolant. I do believe that has been debunked since.

If the 6.7 pump fits I would put one on. I don't see why it wouldn't but I don't know for sure. They sure look the same at a casual glance.

gyman98

It will fit and work just moves a higher volume of coolant

patdaly

LOL, most of us have a hard time building enough heat.........

Clampett

I went ahead and installed the 6.7 pump yesterday along with a factory Cummins thermostat. I will say the my operating temps have dropped (about an 1/8" on the guage, rides right on the 1/4 mark) and I don't see any fluctuation when pulling up inclines like I used to. I'm not sure if thats the pump or the thermostat but I'm happy with it. Heat index here in N. Central Florida is 110 this time of year and pulling my boat would raise my temps so I was looking for increased cooling. I realize that in most parts of the country this won't be needed as these run fairly cool most of the time. All in all, I'm happy with the cooling performance of my truck now we'll see how it does when I hook the boat up this weekend.

Angry Johnny

Excellent, thanks for the report. I'll be putting one on mine when it's time.

w250 guy

I believe i see a 6.7 pump as well when it comes time for a new water pump!

Sent from my iPhone using IB AutoGroup

j_martin

I've made my living engineering fluid heat transfer systems. The only concern with excessive flow is the energy required to move it. The engineer's task is to find that fine line between high performance and diminishing returns.

My next one will be the 6.7 also.

GasganoFJ60

Do you have a picture of the two pumps side by side? How are the props different?

gyman98

5.9:


6.7:


Make sure to buy a pump for a 2007.5-2012 6.7

bigragu

Do you have a cummins part # handy?

Clampett

Cummins # is 2881804. They quoted me around $175. I bought a brand new one from Carquest for $50 (with my wholesale discount)

bigragu

Thanks a plenty for the part # and Carquest tip!

Jim Lane

Are the drive hubs the same diameter on both pumps?
Jim