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Pressure washer pump leaking oil? Here’s what to do

How do I fix my pressure washer pump leaking oil? That was the question my neighbor asked last night. It was her first experience using a pressure washer pump. Just like my neighbor, are you stuck on how you can fix your pressure washer pump from leaking oil? Rather than get yourself worried, I will advise you to get a seat, and relax. In this article, we will walk you through all you have to do to fix a pressure washer pump that is leaking oil.

There are different things you can do to fix a pressure washer pump that’s leaking oil:

  • Buy an Oil seal kit
  • Check your seal regularly
  • Use the right seal to avoid leakage
  • Change any broken or worn-out seal


How to Fix a Pressure Washer Pump Leaking Oil

Fixing a pressure washer pump leaking oil is not as difficult as you may think. If you follow the guide in this article, you should be able to handle yours effectively without the need to go for a repairer. You can fix a pressure washer pump leaking oil by doing the following:

Buy an Oil Seal Kit

The first thing to do is to buy an oil seal kit that fits perfectly with the damaged one from which the oil leaks. Doing this depends largely on the type of pressure washer pump.

Some common pressure washer pump includes; Dewalt 4200, Honda GX 390, Comet ZWD-K 4042 Knowing the make of your pressure washer pump will enable you to buy the right oil seal kit.

Replace the oil seal kit and also replace the water seal kit as well. Some oil seals are made of rubber which makes them easier to remove and re-install.

You can find some pressure washer seal kits here.

Change any broken or worn-out seals

Worn-out or broken seals are some of the common issues associated with washer pumps. A pressure washer comes with different seals distributed throughout the pressure washer.

One of them may break at any time or get worn-out. This automatically creates a leak. It is not just oil that leaks but can also include water.

Broken seals are mostly due to a lack of proper maintenance of the pressure washer. Also, the seal’s contracts and expands. This depends largely on how hot the weather is. High humidity weather can cause the seals to contract and expand and eventually leads to leakage as the weather gets hotter.

Check your seal regularly

A timely and proper maintenance of your pressure washer pump is needed to avoid oil leakage or even a total damage of the pump. To avoid this, ensure you check your seals regularly, at least two or thrice a year and if need be, replace the worn-out ones.

A DIY approach might not be impossible as far as maintaining your pressure washer is concerned but then, some manufacturers have taken steps to ensure end users are unable to do this. If this happens to be the case, visit a regular mechanic who is trained to handle such.

Use the right seal to avoid leakage

If you want your pressure washer pump to last longer than you envisage, ensure that the right seal is properly used. Using a wrong seal for your pressure washer pump can lead to leakage which might eventually lead to its breakage if not repaired on time.

Also, go through the buyer’s guide properly before installing any new seal to avoid further damage to other components of the pressure pump.

Types of Pressure Washer Pumps to Consider

The pump is considered one of the most important parts of a pressure washer since it is the part that produces the water velocity.  Three types of pressure washer pump exist– wobble plate, axial cam, and triplex plunger. Now, let’s see some of the things you need to know about the pressure washer pump types.

Axial Cam Pump

The Axial Cam Pump is known as a swashplate pump. It has a lot of benefits when compared to the wobble pump type. Just like the wobble plate, they do almost the same work except for the spinning of their pistons.

There are two versions of the Axial Cam Pump–fixed and variable. The variable version’s swashplate can be adjusted to any angle you want. What makes the Axial Camp Pump special is that it sucks water by allowing the swashplate to stroke the piston.


The Axial Cam Pump has some considerable advantages. They are more efficient, self-priming, light in weight, compact in size than the wobble pumps. Also, you can adjust the flow of water as you want.


One major disadvantage of the Axial Camp Pumps is that it takes a lot of time to cool down after getting hot. Also, when the pump is not well-balanced, there tends to be excess vibration.

Triplex Plunger Pump

The Triplex Plunger Pump operates and tolerates a very high pressure. It is considered as a professional level pump as it is strong in nature and can operate for long hours without needing maintenance. It does not get hot, unlike the Axial pump.


Triplex plunger pumps have a longer life span than the other types of pressure washer pumps. They are less prone to leaks, cool down in a relatively short time after getting hot and can pump with a higher pressure.


Considering its durability and efficiency over the other two types of pressure washer pumps, the Triplex Plunger Pump is quite expensive. What this means is that you have to cough out a lot of money before you can buy one.

The Wobble Plate Pump

The Wobble Plate Pump is driven by the shaft and it’s considered as the least complicated in the three types of pressure washer pumps. The piston sucks water as the driveshaft pushes the piston back and forth. If you are considering buying one, also consider its pros and cons.


The wobble plate pump is relatively cheap when compared to others. Apart from this, they are capable of producing high pressure, capable of running dry and are also self-priming.


A huge disadvantage is that this type of pump has complex moving parts that are not replaceable. It’s also not optimally efficient performance-wise when compared to others because of the lower water flow.

Things to Consider When Buying a Pressure Washer

If your pressure washer is not repairable you may want to look for a new one. But over the last decades, a lot has changed about pressure washers. As it becomes more affordable, the quality as increased as well. However, buyers of a pressure washer, most times are likely to run into a decision quagmire as it relates to the type to buy, durability, usage

In terms of time management, a pressure washer can greatly improve your ability to manage and clean your properties within a limited time frame. For your ease, we outlined some of the key things you should consider before buying a pressure washer.

Electric or Gas

You’ve made up your mind to get a pressure washer but you are not sure whether to go for the electric or the gas type. Don’t let it bother you much. There are a few things you need to know about both.

One key difference is that the speed and strength differ and they pressurize water differently. The gas-powered washer produces more power but is quite louder while the electric has less power and quieter. In terms of price, the gas pressure washer is more expensive than the electric.

Consider your Budget

Just like other aspects of your life, your budget before buying any property has a huge role to play in your decision making. You’ve known that there is an electric and gas pressure washer but then, how much you are willing to cough out depends on your budget.

The gas pressure washer is quite expensive when compared to an electric pressure washer. There is no harm in going for that which you can afford without going broke. At least, that’s a financial frugality everyone should take note of.


Manufacturers provide a warranty on their products as a means to persuade you to buy them. Before buying, always check the kind of warranty the company is offering. Some warranty covers changing the entire product when something goes wrong while some agree to change only some components of the product that are not working properly.

Since you are buying a pressure washer, going for a warranty that covers at least the engine and pump is something you should look out for. Also, take note of the warranty period.


How easy it is to wheel around and also store is very important when considering a pressure washer. It can be very frustrating to see that your pressure washer cannot easily be moved around or requires a lot of energy to move. When making your choice, go for the one that can be moved about with minimal effort. If possible, test-run it at the shop before buying.

Decide on your working space

Your purpose of use should be paramount before deciding on getting a pressure washer. If you want to use it at home, it is ideal to go for a residential pressure washer. If otherwise, and it will be used at your workplace, your best choice is a commercial pressure washer. The commercial washers are much more powerful and provide much more water pressure than the residential ones.


Pressure washer pressure is measured in Pounds per square inch(PSI) and gallons per minute (GPM). A higher PSI indicates a higher water force while a higher GPM indicates higher water flow from your machine.

Leaking Water from the Pump: Potential Causes and Solutions

When encountering a water leak from your pump but there’s no visible damage, it’s highly likely that the internal piston seals are worn out or broken. From my experience, this can be successfully rectified by a professional replacement of these seals.

The role of these seals is critical, as Penn State University explains; they prevent the fluid handled by the pump from leaking into the environment, thus maintaining efficiency.

• Oil Leaks in Pump: Understanding the Problem

Sometimes, you may come across oil leaks in your pump. In such cases, it’s recommended to disassemble the pump and replace all worn or damaged parts. Just bear in mind that the culprits behind the oil leak could be various components such as seals, gaskets, or pistons.

For an added layer of protection, tightening any loose bolts in the pump assembly can also help in preventing oil leaks.

• Inconsistent Pressure Issues: Identifying the Root Cause

Are you experiencing inconsistent pressure from your pump? One of the primary reasons could be an inadequate amount of water going through the pump. The best way to resolve this issue is to remove and clean the inlet filter.

But, if the problem persists, it’s highly likely that a faulty unloader valve may be causing the inconsistency in the pressure, and you’ll need to get it replaced.

• Low-Pressure Troubles in the pump: Ways to Alleviate

Low pump pressure could be caused by worn O-rings or blocked inlet valves. An initial check of the O-ring is advisable. If it shows no signs of wear and tear, the problem might lie with the inlet valve.

A blocked valve, often loaded with dirt and debris, requires a thorough cleaning to bring the pump pressure back to normal.

• Dealing with Loud Noises from the Pump

Unusual loud noise from the pump is not a situation to be ignored. Oftentimes, the cause of this noise is low oil levels.

In this scenario, it’s best to disassemble the pump, check the oil level, and top it up if necessary. This step is crucial to prevent your pump from overheating and causing more damage.

• Presence of Cloudy or Dirty Oil in the pump

Cloudy or dirty oil is an indicator that water has entered into the crank tank, implying that your pump has worn-out seals. In this case, replacing the seals will solve the issue.

• Considering a Pump Replacement

If you’re grappling with a pump that is over a decade old and has obsolete or hard-to-find parts, a replacement might be a more financially sound decision.

An essential point to note here is that if the price tag attached to replacement parts overshadows half the value of a new pump, it makes more economic sense to opt for a brand-new pump.

• Recommendation on Pump Provider

When it comes to effective solutions for all your pump-related issues, I recommend Hotsy Water Blast. They provide both cold and hot water pressure washer pumps.

Apart from retailing, their services extend to repair and maintenance, offering a comprehensive pre-scheduled maintenance program catering to all makes and models of pressure washer pumps. A great fit for every pump owner, beginner or expert.

• Importance of Washing the Pressure Washer Pump

Regular maintenance of the pressure washer pump is critical to avoid oil leaks. Keeping your pump clean and well-lubricated will not only enhance its performance but also extend its lifespan.

A well-maintained pump is also less likely to leak oil, which can lead to further complications.

• Process of Changing the Pump’s Oil Seal

Changing the oil seal of your pressure washer pump is a relatively straightforward process. Start by locating the oil seal on your washer pump. Using a flathead screwdriver or a seal puller, gently remove the old seal. Be careful not to scratch or otherwise damage the pump during this step.

Once the old seal is removed, clean the area where the seal used to be. Use a clean cloth to remove any remaining oil or debris. Then, take your new seal and apply a thin layer of oil to it. This will help the seal slide into place more easily.

Next, carefully insert the new seal into the pump. Make sure the seal is positioned correctly and is seated evenly in the pump. Lastly, use a rubber mallet to gently tap the seal into place.

• Tips on Preventing Oil Leaks

To prevent oil leaks from the pressure washer pump, it’s essential to tighten the diesel filter and machine filter. You should ensure these components are securely fastened, but be careful not to overtighten them, as this could damage the threads or seals.

Here’s a helpful tip: when tightening these filters, turn them until they make contact, and then give them another half-turn. This should secure them sufficiently without causing damage.

• Regular Checks on Oil Levels

It’s crucial to check oil levels in a pressure washer pump regularly. If oil levels are low, the pump may operate ineffectively and be more prone to leaks. Regular checks ensure that the pump always has an adequate oil quantity, which keeps it lubricated and reduces wear and tear.

• Potential Dangers of Leaking Oil Pumps

A leaking oil pump in a pressure washer poses serious risks. Besides causing environmental damage through oil contamination, leaks can also result in irreversible damage to the pump and other components of the machine. It’s critical to address oil leakage issues promptly to prevent costly repairs or replacements.

• Sources for Oil Seal Kits

Oil seal kits for pressure washer pumps can be readily purchased from many sources. Online marketplaces such as Amazon and eBay are convenient platforms, while local hardware stores could also carry these kits. Additionally, the website of the washer model’s manufacturer is another reliable source.

• Visual Inspection of Seals

To inspect the seal visually, look for any visible signs of wear, damage, or oil seepage. If the seal appears deformed or crushed, it likely needs replacing.

• Consequences of Using Wrong Seals

Using the wrong seals can lead to an ineffective seal, resulting in oil leaking from your pressure washer pump damaging the pump itself or the washer’s other components. Always consult your user manual or contact the manufacturer if you are uncertain about which seal to use.

• Recommended Oils and Lubricants for Pressure Washer Pumps

Every pressure washer pump has recommended oils and lubricants, typically specified in its user manual. These vary among manufacturers and models.

Refer to the EPA’s guide on selecting and using lubricants for more information. Using unsuitable oils can potentially damage the pump or decrease its lifespan.

• Causes of Oil Leaks

Oil leaks may arise as a result of broken gaskets, pistons, or seals in your pressure washer. Such ruptures can lead to undesired outcomes, curbing the equipment’s performance and hastening its wear and tear. Hence, having an understanding of the causes can help holistically prevent these issues.

• Importance of Regular Maintenance

To keep your pressure washer in optimum condition, regular maintenance is paramount. This routine process involves checking the oil level. In addition, inspect seals and other parts for any signs of damage.

Although it might seem time-consuming, this preemptive measure goes a long way in preventing oil leaks and enhancing the lifespan of your pressure washer. For a more detailed guide on maintenance procedures, visit the US Department of Energy’s website on Equipment Maintenance.

• Understanding Oil Levels

Having too much oil in your pressure washer may cause an overflow, which could mistakenly be identified as a leak. Therefore, it is crucial to check the oil levels regularly. This will ensure that your machine operates at peak efficiency and also averts potential oil leaks.

• Milky Oil and Damaged Seals

One sign of a damaged seal is the presence of milky oil. In such scenarios, you would need to have the seal replaced. Otherwise, ongoing use might severely impair the performance and longevity of your pressure washer.

• The Benefits of Manufacturer-Recommended Products

I strongly recommend using manufacturer-recommended products. These include lubricants for the pump. Utilizing these specified products can significantly decrease the likelihood of oil leaks in your pressure washer.

• Effects of Weather Conditions

Operating your pressure washer in the appropriate weather conditions is a preventive measure toward seal expansion and fitting issues. It’s yet another simple step to ward off potential oil leaks and maintain the overall efficacy of your equipment.

• White Oil and Its Implications

If you notice white oil in your pressure washer, this is often a result of water infiltrating the oil gasket. This can cause substantial damage to your machine. Therefore, it should be addressed promptly.

• Choosing the Right Oil

As advised by the manufacturer, non-detergent 30W oil or all-purpose engine oil should be used in your pressure washer. Adhering to these guidelines ensures compatibility performance and aids in the avoidance of malfunctions such as oil leaks.

• Timing of Oil Replacement

Oil should be replaced every 50-60 hours of usage or at the commencement of spring or the conclusion of winter. This rule plays a fundamental role in maintaining the smooth operation of your pressure washer.

• Risks of Prolonged Unused Oil

It is highly advised not to leave unused oil in the pressure washer for extended periods. This is because the oil can thicken over time and potentially cause problems in the machinery.

• The Use of Synthetic Oil

Generally, it is safe to use synthetic oil in your pressure washer. Regardless, non-detergent oil is the perennial choice due to its adaptability to the machine’s functionality.

• Validating with the Owner’s Manual

Before using 10W40 oil or any other type of oil in your pressure washer, make sure to consult the owner’s manual. This step is essential to confirm compatibility and prevent the risk of oil leaks.

In conclusion, regular maintenance, appropriate oil choices, and timely replacements combine to ensure the efficient functioning of your pressure washer. Following these guidelines should preserve the longevity of your equipment, reduce oil leaks, and optimize performance.

The Potentials of Drain Plugs Causing Leaks

Useful yet sometimes overlooked are drain plugs. Ideally, they should help maintain the proper operation of various equipment, including pressure washers. However, in certain instances, drain plugs can become a hitch if they often cause leaks.

Handling a leaking pressure washer can be tricky, but sometimes, the solution can be as easy as tightening the drain plug. The drain plug is essentially the “stopper” of the pressure washer, preventing water or oil from flowing out unnecessarily. When this becomes loose, leaks are prone to happen.

Assessing a leak usually requires checking the tightness of the drain plug. If a leak persists despite the drain plug being adequately tightened, a deeper issue may be at play, which may require professional intervention.

• The Role of Seals, O-rings, and Other Engine Parts in Leakages

Not all leaks are caused by drain plugs. Sometimes, the seals, O-rings, or engine parts can be potential culprits. These components are integral to your machine’s performance, and as they wear out over time, leaks may occur just the same.

Often under the radar, engine parts, pumps, seals, and O-rings are all critical in maintaining the machine’s overall functionality and preventing leaks.

More often than not, when a leak occurs in these parts of the machine, it’s best to seek professional assistance. Even the tiniest leaks in these components can indicate a more significant problem if not addressed immediately.

Professionals have the necessary skills and tools to address such problems accurately. They can provide a comprehensive assessment of the issue, ensuring that further damage is prevented. The U.S Department of Energy highlights the urgency in addressing pump leaks as they can lead to severe energy loss.

• The Role of Regular Maintenance Checks in Preventing Leaks

Regular maintenance checks can be tedious, but they are paramount in preventing leaks. Inspecting the seals for any damage, removing physical debris, and examining compression fittings can ensure that the machine operates efficiently.

A regularly checked washer means less chance of leaving a pressure washer unattended with leaks. This not only helps you identify and prevent issues before they become grave and costly but also prolongs the lifespan of your machine.

• Lower Maintenance with Electric Pressure Washers

Maintenance tasks can be a grim prospect for some. If you’re one of these people, opting for a low-maintenance electric pressure washer might suit you better.

Electric pressure washers are known to require less maintenance compared to their gas-powered counterparts. Therefore, they can be a more convenient option for those who want to avoid the time and effort involved in regular maintenance.

Of course, this doesn’t mean that electric pressure washers are immune to leaks or other damages. However, their overall design and less demanding maintenance requirements may be more suitable for users seeking a simpler, more manageable option.

Remember, regular check-ups are still recommended, even with low-maintenance models. Keeping a record of your maintenance checks can help track if there’s an improvement or deterioration in your washer’s performance.

• Closing Remarks

Leakages can be prevented with correct and timely measures. Be it the checking of drain plugs, seals, engine parts, or investing in low-maintenance equipment; every step counts towards preserving the functionality and efficiency of your pressure washer.

Appropriate maintenance measures can save you from falling into a pit of unnecessary expenses and worries.

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  1. Carrie Ruiz says:

    Thank you for providing information on the types of pressure washer pumps and how to choose the right one. Very helpful!

    • Allard Vdhooft says:

      Thank you for your feedback, Carrie! I’m glad you found the information on pressure washer pumps helpful. Let me know if you have any more questions!

  2. Jill Long says:

    Wow, this article is so informative! I now know how to fix my pressure washer pump leaking oil. Thank you for breaking it down into simple steps for beginners like me.

    • Allard Vdhooft says:

      Thank you so much, Jill! I’m glad the article was helpful to you. Good luck fixing your pressure washer pump!

  3. Clayton Morrison says:

    The section on potential causes of water leaks from the pump was eye-opening. I will keep an eye out for those issues in my pressure washer.

    • Allard Vdhooft says:

      Thank you for your positive feedback, Clayton! It’s great to hear that you found the information on potential causes of water leaks from the pump eye-opening. Keeping an eye out for those issues will definitely help you maintain your pressure washer.

  4. Bryan Lane says:

    I never knew that using the right seal is so important to avoid leakage in a pressure washer pump. Thanks for the insight!

    • Allard Vdhooft says:

      Thanks for reading, Bryan! Using the right seal in your pressure washer pump is essential to prevent leakage. Feel free to reach out if you have any more questions.

  5. Tonya Pearson says:

    The advice on maintaining the pressure washer pump to avoid oil leaks is crucial. Thank you for emphasizing the importance of regular checks.

    • Allard Vdhooft says:

      Thank you, Tonya, for your feedback on the importance of maintaining pressure washer pumps to prevent oil leaks. I’m glad you found the information helpful. Happy cleaning!

  6. Louella Soto says:

    The information on regular maintenance and checking seals to prevent oil leaks is invaluable. Thank you for sharing!

    • Allard Vdhooft says:

      Thank you, Louella! I’m glad you found the information about checking seals to prevent oil leaks valuable. Make sure to keep up with regular maintenance to keep your pressure washer in top condition.

  7. Victoria Mitchell says:

    The tips on choosing the right oil for a pressure washer pump are very helpful. I will make sure to follow those guidelines.

    • Allard Vdhooft says:

      Thank you, Victoria! I’m glad you found the tips helpful. Remember to regularly check and maintain your pressure washer pump to prevent any oil leaks in the future. Happy cleaning!

  8. Dolores Rogers says:

    I appreciate the recommendations on how to deal with inconsistent pressure issues in a pressure washer. Very practical advice!

    • Allard Vdhooft says:

      Thank you, Dolores! I’m glad you found the advice practical. Let me know if you have any other questions or if there’s anything else I can help with.

  9. Lucille Taylor says:

    Wow, this article is so informative! I now know how to fix my pressure washer pump leaking oil. Thank you for breaking it down into simple steps for beginners like me.

    • Allard Vdhooft says:

      Thank you, Lucille! I’m glad you found the article helpful. Good luck fixing your pressure washer pump!

  10. Kent Miller says:

    Great tips on fixing a pressure washer pump leaking oil. I appreciate the detailed explanation of the steps involved.

    • Allard Vdhooft says:

      Thank you, Kent! I’m glad you found the tips helpful for fixing your pressure washer pump leaking oil. Let me know if you need any more assistance!

  11. Christy Bennett says:

    I had no idea that weather conditions can affect seal expansion and fitting in a pressure washer pump. Good to know!

    • Allard Vdhooft says:

      Thank you, Christy! Weather conditions can indeed impact pressure washer pump seals. Regular maintenance and using the right seal are key to preventing leaks. Glad you found the information helpful!