Dodge Cummins Diesel Forum banner
  • Hey everyone! Enter your ride HERE to be a part of September's Cummins of the Month Challenge!
1 - 20 of 36 Posts

·
Premium Member
Joined
·
700 Posts
Discussion Starter · #1 ·
Not sure if this is the right place for this, but it involves Cummins powered trucks from 1989-2014, so I decided to put it here. Feel free to move it if you feel it belongs somewhere else better.

Through the years, Cummins has gone through a few different water pump "styles". As far as I know, any of the 3 that I've discovered will fit on 89 to current Cummins Engines.
Listed, in order from oldest to newest:
1. Closed vane design
2. Open vane, metal
3. Open vane, plastic/composite

I've attached pictures of the 3 styles made by Murray, which appear to be spot on as far as replicating the OE style.
At some point, I had my 08 Dodge 6.7L Cummins water pump fail, and was forced to replace it with an enclosed pump, as the parts store had nothing else. That unit failed in 100 miles (crappy cheap aftermarket pump). I then picked up a Cummins OEM open metal fin style unit down the road and ran that. I ran that for a few thousand miles but noticed that the coolant temperatures ran about 10 degrees warmer.
I then switched back to an OEM 6.7L Cummins water pump and the temperatures went back to normal.

I've talked to Murray (the aftermarket company that makes the 3 pictured water pumps), and while they couldn't give me actual flow numbers, they indicated that the Closed Vane design flows the most, followed by the composite finned late model water pump, with the open metal vane pump flowing the least.
He also said that Cummins had issues in colder climates with "too much" cooling, causing issues with heat in the cab, so they changed water pump designs going forward..
This makes sense to me, as overall coolant temperature, the way I understand it, is the hotter the coolant, the cleaner the engine will run, emissions wise, which would make sense to reduce the water pump flow to keep the temperatures up.
As we all know, there are cooling issues with the 3rd generation 5.9L & 6.7L Cummins when towing heavy, (moreso with the 6.7L Cummins due to the added "heat load" of the EGR cooler) and the poor radiator design (inlet at the top, outlet 2/3rds the way down the radiator- May have those backwards) the point is, the bottom 1/3rd of the radiator doesn't do its full duty cooling wise because the water wants to travel from the inlet to the outlet, somewhat skipping the bottom.

Does anyone have any input on the 3 pumps, as far as flow?
Does it make sense that the closed/covered vane design would flow more?

Thanks for reading, hoping to get some good input on this subject.
 

Attachments

·
3 footin' through life
Joined
·
12,304 Posts
I don't have any input except that I've been confused about the differences. Thanks for helping clear it up. I have a spare pump waiting here and it has a closed design. I can't recall what the one in the truck is.
 

·
Cowboy AKA Equality State
Joined
·
994 Posts
Good information.
:agree2:

I sure wish I'd have stumbled on this thread back when my '09 lost the water pump! I figured that something changed (bolt pattern etc...) over the years and is the reason that dealers are now putting sand into the Vaseline. :spank: This is proof that they are using the sand for traction instead!! :shock:

I am upset at the fact that I paid so much for a part that was in the toolbox of my '92 the whole time!!
 

·
Registered
Joined
·
1,302 Posts
Ive never seen that closed one before. the water pump went out in my 13 @ 30000 miles and the autozone one was open fin metal. pretty ridiculous it only lasted 30k with zero towing...atleast its like a 30 minute job
 
  • Like
Reactions: justhalc

·
Registered
Joined
·
228 Posts
Does anyone have the part# for the Closed Vane design pump?
 

·
Premium Member
Joined
·
8,041 Posts
I figured this out while I was messing with my electric fan setup:

This was the thread I originally found that turned me on to this idea: Water pump upgrade

Just now, I went and researched it a bit more, and found there's more to the story: http://www.cumminsforum.com/forum/g...-cummins-water-pump-comparison-tech-info.html

The closed-vane model he mentions was factory from 89-98. For 98.5-07, they use the open vane metal pump. The 07.5 and up trucks use the open vane composite impeller. The 12v closed-vane pump flows the most, the 24v/3rd gen pump flows the least, and the 6.7 pump flows in the middle. This is also consistent with the first article I read. For a 24-valver, the 6.7 pump would be an upgrade. Unfortunately for us, it is not. Both other ones are a downgrade. And, regarding the part about the Cummins engineer saying 5.9 pumps are okay only "in a pinch," this is correct in the context of a 24v pump being a downgrade from a 6.7 pump. Unfortunately he was either unaware or neglected to mention that all 5.9 pumps are not created equal, as, once again, the 12v whoops up on the newer trucks. :stirpot:

Cummins part number for the closed-vane pump is 3802004.

The Gates version can be had at Geno's for $42:

Water Pumps - WATER PUMP - GATES ('89-'98, 5.9L)
 

·
Registered
Joined
·
5,209 Posts
interesting, but I imagine the same issues will persist as long as the pump is treated poorly by the truck owner. There is still a bearing in there that is lubricated by the coolant, it needs clean, properly mixed coolant to survive.
 

·
Premium Member
Joined
·
1,055 Posts
So if I'm understanding this correctly the old school 12v water pump is the best?
 

·
Premium Member
Joined
·
8,041 Posts
interesting, but I imagine the same issues will persist as long as the pump is treated poorly by the truck owner. There is still a bearing in there that is lubricated by the coolant, it needs clean, properly mixed coolant to survive.
No, there's not. There are two seals on either side of the bearing assembly, the outer seal keeps dust from entering and the inner seal keeps coolant from entering. There is at least one weep hole between the inner seal and the inner-most bearing. The weep hole is there so that when the seal starts to fail, the coolant has a place to go that isn't into the bearing assembly. Sometimes there is even a second seal between the weep hole and the bearing, in this case there is a second weep hole, the purpose of which is to provide the bearings with a vent to atmosphere.
 

·
3 footin' through life
Joined
·
12,304 Posts
Found a plastic impeller pump in the core 6.7 short block I've got. Just thought I'd mention that.
 

·
Registered
Joined
·
5,209 Posts
No, there's not. There are two seals on either side of the bearing assembly, the outer seal keeps dust from entering and the inner seal keeps coolant from entering. There is at least one weep hole between the inner seal and the inner-most bearing. The weep hole is there so that when the seal starts to fail, the coolant has a place to go that isn't into the bearing assembly. Sometimes there is even a second seal between the weep hole and the bearing, in this case there is a second weep hole, the purpose of which is to provide the bearings with a vent to atmosphere.
I was thinking that when they fail sometimes the block pressure can't escape fast enough esp for the guys that shut off as soon as they put the truck in park. I've seen it happen where the water pressure blows the pulley right off the housing like a water cannon. Simply because they don't give it time to idle and relieve the pressure.
 

·
Premium Member
Joined
·
8,041 Posts
I haven't seen one literally blow the pulley off, but I've definitely seen one where coolant was forced through the entire bearing cartridge and out the external shaft seal because of two clogged weep holes.
 

·
3 footin' through life
Joined
·
12,304 Posts
One of mine failed that way. Coolant gets flung everywhere on the fan and belt system.
 

·
Registered
Joined
·
2 Posts
Pulley sizes

I have been fighting replacing the water pump and belt for 2 days. What I have found is that the pump I pulled off my 2013 has a smaller pulley than the Murray replacement I got at O'reillys...and my stock MOPAR belt (046627751AA) would not fit. barely too short with the tensioner bottomed out on the ac pulley. I had to return the Murray and buy the OE cummins from the dealer and will be putting it on tonight.

Anyone else run into this issue? Or is my truck a unicorn?
 

·
Registered
Joined
·
2 Posts
got it done

I got it all done...had to go buy the cummins pump with the small pulley from the dealer...MOPAR #68210961AA001 also used the MOPAR belt #04627751AA (124") still had to loosen the idler to allow it to deflect just a bit to get the belt to clear the alternator pulley. took 3+ gallons to refill. Overall not a super difficult job IF you have the correct parts available.

MOPAR pump has the small pulley 3.2" dia
Murray and others seem to all have the 3.4" did

I had O'reillys cross the Cummins number (4309429) on the box that was covered by a MOPAR label and it referenced the large pulley Murray pump I was returning. I had tried to find a belt of 125 or 126 to see if that would work but did not find one available to me.

I will be buying a spare pump and belt and keeping it in the truck...tool wise it took a 10mm, 13mm, 15mm wrenches and sockets, a tensioner tool and the container to catch the coolant. probably not a quick side of road fix due to the cool down time to let you remove the coolant and pump but doable if you have the time for cool down and also have 3+ gallons of fluid for coolant.
 

·
Registered
Joined
·
166 Posts
I was thinking that when they fail sometimes the block pressure can't escape fast enough esp for the guys that shut off as soon as they put the truck in park. I've seen it happen where the water pressure blows the pulley right off the housing like a water cannon. Simply because they don't give it time to idle and relieve the pressure.
IF a water pulley came apart from the housing, it's not from pressure build up. There are so many other places that pressure would go FAR before pushing the impeller shaft out the housing: The DESIGNED place would be the radiator cap and into the coolant reservoir. After that, any of the rubber hoses that carry coolant, the radiator seams, even the radiator itself. That's why a cooling system has a pressure rated cap. The cap pops open when pressure reaches a certain level, and overflows into the 'puke tank'. As things cool back down, the coolant in the puke tank is then sucked back into the cooling system through the one-way flow design of the cap and filler neck.


IF the shaft popped out, (and nothing else) it's because the shaft seals/bearing have already failed. And, I will add, have failed so badly, the bearing assy is falling apart. If this does happen, you're losing coolant like crazy.

PE
 
1 - 20 of 36 Posts
Top