Best Water Pumps For 5.9 Cummins – Buyer’s Guide [2021]

| Last Updated: December 24, 2021

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Are you looking for a water pump for your 5.9 Cummins engine?

With a vast majority of such pumps present in the market, it gets hard to pick the best one without spending enormous amounts of time on proper internet research. 

Here is the detailed buyer’s guide on the best water pump for 5.9 Cummins engines. 

Comparison of the Best Water Pumps For 5.9 Cummins

  • Easy on the pocket
  • Cummins Water pump for the year 2007 to 2012 Cummins engine
  • Comes with an O-ring which is also known as a packing or toric joint
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  • Assembling it is a walk in the park
  • Cost is very efficient, making it easily affordable
  • Cummins water pump 3.9/5.9L Cummins is perfect for the 1989-2002 Cummins engine
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  • Perfect replacement to cool down the engine
  • Ideal pump for the 2003-2007 Cummins engine
  • Extremely easy to install to the already-fixed engine
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What Purpose Does a Water Pump Serve?

A water pump is a machine used to navigate the fluid. From placing it inside a car engine to using it to filter a pond, one can use it in homes, offices, and even fire stations. Have a look at three ways you can use a water pump:

Vehicle’s Cooling System 

A water pump in the engine of the vehicle is used to control the flow of water in the engine. It allows the coolant to circulate the radiator and engine. Its main purpose in the engine is to take away the heat of the combustion. If your car doesn’t have a water pump, which is extremely unlikely, then its engine would quickly overheat. 

Fire Safety System

In the case of a fire emergency, a water pump is installed to ensure the continuous and consistent flow of water. This helps the water get to hard to reach places that aren't reached with normal pressure. 

Regulate Pressure

One can use a water pump to regulate the flow of water in homes, businesses, or even in the engines of vehicles to reach where it is necessary. It can especially reach places where it is hard for water to reach with a normal flow and pressure. 

How to Choose a 5.9L Cummins Water Pump

As we have mentioned already, choosing a water pump for a 5.9L Cummins is a tricky job. One has to consider a lot of factors. A good water pump should have the following three features, so one must consider these qualities when opting for a 5.9L Cummins water pump.


To avoid tragedies like water pump failure, one must know that the bearing of the water pump holds high-importance. In the case of a malfunction in the bearing, there will be a leak in the water pump. Usually, it is quite noticeable due to its change of sound. Therefore, one must choose a water pump with a sound bearing.

Weep Holes 

Most of the water pumps have weep holes. These are designed for multiple functions. When choosing a water pump for a Cummins 5.9L, you have to be certain regarding the leak. If there is a leak in the weep hole present at the bottom, it is doomed to fail.

Bearing Seal

Watch out for the material and nature of the bearing seal, as it holds significance. Contamination often causes failure of the water pump and the bearing seal is there to avoid the contamination.

Keep these features in mind, as they will help you choose the best!

Review of the Best Water Pumps for 5.9L Cummins

Let us look at the main features, pros, and cons of the best water pumps for 5.9L Cummins. Choosing one of these will ensure that your engine stays in top condition. 

1. Cummins Water Pump


  • Fits easily like a stock part
  • Can reuse the factory bolts
  • Extremely easy to assemble and fix all the parts
  • Economical and budget-friendly. Its starting price is $20 per month
  • Flow and pressure of the water and the coolant generated from this pump are great


  • Takes a while to assemble and install the whole system.

What Recent Buyers Report

About the Cummins water pump, the recent buyers reported and applauded the flow of the liquid and coolant as it was perfect for the engines of their particular vehicles. Some reported that the flow was too perfect, and even a slight increase wouldn’t suit them well. If you are looking for a pump with perfect flow, then you have found it!

Why it Stands Out to Us

The very fact that it is a perfect machine one can get at a relatively low cost makes this unit stand out. In addition to this, how can we not talk about its impeccable water pump? This is perfect for 2007 to 2012 engines. Lastly, you don’t have to pay a special visit to the mechanic to install it, you can do it yourself, as well.

Who Will Use This Most

People who drive a Cummins engine and are looking for a new water pump should opt for this. If your vehicle’s engine gets exhausted and gets overheated very quickly, then you need a new pump. People wishing to cool down their engines will greatly benefit from this.

Bottom Line

This Cummins water pump for 2007 to 2012 Cummins engines is incredibly easy to install, with a perfect flow of water. If you are looking for a Cummins water pump replacement for a Cummins engine, this would be an ideal fit.

2. Cummins Water Pump 3.9/5.9L Cummins


  • Very easy to install
  • Comes with an O-ring
  • Only costs twenty dollars per month
  • Not so hard on the pocket, considering its relatively lower price
  • Stock replacement piece makes it easy to find and is cheap


  • If you are a rookie, then installing it would take a couple of extra seconds

What Recent Buyers Report

Recent buyers reported that assembling and laying out all the parts of the water pump was easy and manageable, but installing it was a bit time-consuming. In addition to this, most buyers report satisfaction with the water flow. Overall, recent buyers report positive comments.

Why it Stands Out to Us

This wonderful and remarkable water pump stood out to us because it is budget-friendly and the fact that there is no rocket science involved in this. For a 3.9/5.9L Cummins engine, this is the perfect water pump, so buy one right away. We assure you, it is worth every single penny.

Who Will Use This Most

Drivers who wish to cool down their radiators and keep their vehicles running smoothly should opt for this. Plus, as mentioned earlier, it is easily affordable. So, people looking for a cheap option should also choose this one. If it satisfies your needs, then you must go for it!

Bottom Line

Cummins Water Pump 3.9/5.9L Cummins for 1989-2002 Cummins engines comes with an O-ring, is easy to fix, and comes with a simple-to-understand instruction manual. If your engine falls in this category, then you must get this water pump. Have a look at the pros and cons and decide for yourself.

3. Mopar OE Replacement Water Pump


  • Also comes with an O-ring
  • Easily affordable, making it an ideal pick
  • Cools down the engine in a very short time
  • Direct replacement for Dodge Ram with a Cummins engine
  • Perfect water pump to fix an already-installed engine


  • Your vehicle must have a Cummins engine 2003-2007

What Recent Buyers Report

Recent buyers shared positive reviews regarding this Cummins water pump. The fact that it is compatible with the built-in Dodge truck engine makes it famous among its users. In addition to this, the flow is very well-adjusted, making it a perfect and remarkable pump to cool down a Cummins engine.

Why it Stands Out to Us

The very fact that made it most likable among its users is that it is adjustable to most Cummins engine makes. This is what makes it stand out from the rest. In addition to this, we love machines that are easily assembled by amateurs. If this is what you are looking for in a water pump, then you've found your match.

Who Will Use This Most

People who drive Dodge and are looking for a water pump replacement for their Cummins engine would greatly benefit from this product. This is an ideal water pump replacement to allow water to navigate around the engine. If you are looking for these features, then this is the perfect pick for you.

Bottom Line

The Mopar OE Replacement Water Pump is a perfect replacement for the worn-out engine in your hood. With an affordable price tag, this is an ideal pump for your needs. So, give your engine a cooling system and purchase this economic water pump for a smooth, worry-free drive.

Perks of Upgrading Your Water Pump

It’s no surprise that upgrading your water pump comes with its set of benefits. These include:

Keeps Your Engine Normalized 

When you start the engine, the water drawn from the water pump goes through the engine. Water acts as the coolant to normalize the temperature of the engine. If you find yourself adding water to the reservoir more than usual, you hear an unusual sound when you start the engine of your vehicle, and/or the temperature is higher than the normal, then it is time to replace or upgrade your water pump.

Easily Affordable and Easy to Install 

When you opt for a new water pump, you don’t have to take a huge amount out of your pocket, as these are affordable. So, it is worth investing in one of these models. In addition to this, if you don’t want to stop by the mechanic and pay him more to install the water pump, then you can easily do it yourself. 

No Need to Change the Engine 

If you don’t wish to replace and update your previous engine, then don’t worry. The Cummins water pumps listed above are easily fixable with the already installed engine. 

With these irresistible perks, it is extremely easy and convenient to upgrade or replace your water pump. Cross-check your engine types and select the water pump that’s perfectly suitable for the engine of your vehicle. Make a wise pick and don’t hesitate to upgrade.

How to Replace a Cummins Water Pump

If you are thinking about replacing a water pump on a Cummins 3.9/5.9L, know that this whole replacing phenomenon is not rocket science. The entire process is extremely simple. All you have to do is follow the following steps:

  1. Take out the cables and attach them.
  2. Empty the inner freeze completely.
  3. Make sure the airflow tank is open and the radiator cap is off.
  4. Clean out the area around the water pump and then take the old pump out.
  5. Take the new water pump out of the package and get the O-ring and bolts out.
  6. Place the ring inside the water pump.
  7. Finally, place the entire assembly carefully inside the engine.

Just remember to clean off the grease from the pipes and tubes of the engine. For more details, key tips, and tricks regarding replacing a Cummins water pump, you can watch this video to let the coolant from a new water pump flow through your radiator. Watch this detailed video, follow each step very carefully, screw in all the nuts and bolts, and you will have a new water pump in your engine in no time.


Replacing the water pump of a Cummins engine is a must if your previous one is acting up. Just consider factors such as price, water flow, and compatibility. Multiple Cummins water pumps are available in the market to match your Cummins engine. Explore all of your options and make a wise pick.

Sean comes from the forums actually and drives an OBS Ford. He writes fantastic DIYs and knows his way around a camera, too. We keep him caffeinated and away from DPF filters to avoid another rant about recent emissions restrictions.