Pressure washing is intricate, and the best pressure washer pump oil is one of the things that make it possible. Your pressure washer is an incredibly useful tool – it helps you keep your home, yard, patio, garage, car, work tools, and machines, and so much else in pristine condition. However, regular maintenance of the washer itself is necessary to keep the machine running well and retain its peak performance month after month, year after year.
A big part of that maintenance is keeping the moving parts lubricated to minimize friction, both on the motor and the pump. However, you can’t use the same type of oil for these two parts, so picking the right pressure washer pump oil is important for keeping your machine alive and well. Read on to learn everything you need before changing your pump oil like a pro!
Why Does a Pressure Washer Pump Need Oil?
It doesn’t matter if you’re a professional who washes cars, machinery, or buildings on a daily basis, or you’re a homeowner who mostly uses a pressure washer to clean your home vinyl siding once a year – if you at some point invested in a pressure washer, you want it to last a long time. Just like with any type of machinery, your pressure washer requires regular maintenance to work well. An important part of maintenance is oiling your pump.
It’s quite simple: to work, the inner parts of a pressure washer pump need to move at great speeds. When parts that touch one another move, the movement creates friction between them. Friction creates heat, and the longer or the faster the parts move, the bigger the chances of overheating become. Excess heat can easily cause damage to parts of the pump, some due to the material not being able to withstand the heat (for example rubber that melts), and others due to the expansion of materials or water that happens at high temperatures. It’s easy to see how easily this simple issue can result in a disaster.
To prevent the buildup of friction, there has to be lubrication between the moving parts. Lubrication makes sliding next to one another easier for the parts and heavily reduces, nearly nullifying friction. This prevents overheating and helps your pressure washer pump live a long, happy life.
1. Which Type of Pressure Washer Pumps Needs Oil Changes?
Whether or not you should change the oil in your pressure washer pump depends on the type of pump your washer utilizes. There are three types of pressure washer pumps that are commonly used in commercially available models, and only one of these types actually requires oil changes.
1.1. Axial Cam and Wobble Plate Pumps
If your pressure washer puts out pressure lower than 2500 PSI or uses a water flow weaker than 2 GPM, chances are that it uses a wobble plate or an axial cam pump. These two types of lower-rated pressure washer pumps are factory sealed, and that means that they don’t need oil changes. It’s simple – these are very cheap to make and replace, so when it stops working, it’s cheap enough to replace them.
However, you should note that the PSI and GPM rating alone is not a foolproof way of determining your washer’s pump type. If you have a gas pressure washer with exposed components, you can determine the type of pump just by looking at it. If you own a model that is covered in a plastic casing, check your washer’s specifications in the user manual or on the manufacturer’s website to find out which type of pump it uses.
1.2. Triplex Pumps
It doesn’t matter if you own a gas or an electric-powered pressure washer: triplex pumps are common in every type of washer for their supreme power and durability. This type of pump utilizes three pistons to pump out water at consistently high pressure, and because of this unique construction, they’re very easy to recognize.
Replacing a triplex power washer pump is expensive, as they have an intricate design. On the other hand, they have a virtually unlimited lifespan, but of course, they can break due to overheating. Because of that, regular maintenance and oil changes make all the difference in the longevity of your pressure washer.
Best Pressure Washer Pump Oils Comparison Chart
Briggs & Stratton Synthetic Oil for Pressure Washer Pump 15-Ounce
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Generac 6656 Pressure Washer Pump Oil SAE 30 20-Ounce
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Simpson 7106737 Pressure Washer Pump Oil 1 Pint
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CAT Pumps Pressure Washer Pump Oil, 21 Oz.
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Mi T M AW-4085-0016 Power Washer Pump Oil
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General Pump 758-115 Pressure Washer Pump Oil Black
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Mag 1 60694-6PK Pressure Washer Pump Oil – 1 Quart Pack of 6
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Best Pressure Washer Pump Oil Reviews
1. Briggs & Stratton Synthetic Oil for Pressure Washer Pump 15-Ounce
If you’re looking for a big name brand synthetic oil that comes at a very reasonable price, look no further than Briggs & Stratton 6033 Synthetic Oil for pressure washer pumps.
The viscosity of this synthetic oil is labeled in the gear oil SAE system, and it measures SAE 75W90. If your pressure washer requires this particular type of oil, we highly recommend this particular product. This viscosity label roughly translates to SAE 10W40 in the general engine oil measurement system, so it’s likely a good fit for any pressure washer pump that has 10W40 as recommended viscosity. Double-check the label to see if this oil will fit your washer’s pump. It’s the ideal pick to use in Briggs & Stratton brand pressure washers.
When it comes to packaging, you’ll be happy with the sturdy black plastic bottle of this product. It’s resalable, and it features a graduated see-through piece that will allow you to accurately track how much oil you pour and how much you have left. In the bottle, you get 15 fluid ounces of the product.
2. Generac 6656 Pressure Washer Pump Oil SAE 30 20-Ounce
Generac is another popular pressure washer brand, and here we have their original 6656 pressure washer pump oil.
This high-quality oil comes at a rather low price. That’s especially because you get as much as 20 fluid ounces in the bottle. The bottle itself is a commonplace black plastic bottle, and it features a slit of transparent plastic on the side with volume labels. This will make it easy to pour just as much oil as you need, and it will let you know how much you have left.
This SAE 30 oil is specially formulated for use in pressure washer pumps. It will help your pressure washer pump run smoothly, and it will prevent excessive friction which can damage your power washer. So, if you have a pressure washer that requires SAE 30 oil, and especially if your unit is made by Generac, we highly recommend this oil. You can find more info regarding performance and safety here.
3. Simpson 7106737 Pressure Washer Pump Oil 1 Pint
If you have a Simpson brand power washer, it’s highly recommended to use the brand’s own line of power washer pump oil. However, you should rest assured that if the specifications of this oil fit, you can feel free to use this high-quality oil in pressure washers made by other manufacturers as well.
This genuine Simpson product comes in a regular black plastic bottle that holds 16 fluid ounces of oil. Sadly, the bottle doesn’t seem to feature any kind of graduated transparent slit that would help you see how much you’ve used or how much oil you have left inside the bottle. However, given that it’s a 16-ounce bottle, it will be simple to calculate.
This oil is a Simpson recommended SAE 15W40 premium oil. It doesn’t foam up and contains no detergents, so it’s perfect for any power washer pump that requires that kind of viscosity rating. It’s especially highly recommended for Simpson brand pressure washers, but of course, you can use it in any other brand if the viscosity is suitable.
4. CAT Pumps Pressure Washer Pump Oil, 21 Oz.
Next up, we have a popular oil made by CAT, a well-established power washer pump manufacturer. This oil is of very high quality, and it comes at a very affordable price.
The CAT product is a petroleum-based oil that’s graded on the hydraulic scale of viscosity, where it measures ISO 68. Given that this is an equal of SAE 20W, it’s a tiny bit thicker than the standard SAE 10W30 oil that’s used in the majority of pressure washers. Therefore, you should only use this oil if your pump label or user manual specifically ask for ISO 68 or SAE 20W oil. In general, it’s suitable for any pressure washer that uses a Comet, General, AR, or a CAT pump.
The quality of this oil is reflected in its carefully-chosen additives, which will protect your pump from wear, oxidation, and corrosion. Of course, it contains no detergent. You can find more safety and performance information here.
When it comes to packaging, this oil is contained in a regular black plastic bottle. On the side, you can find a two-unit graduated sight strip that will help you use up the 21 fluid ounces that come inside without wasting a drop.
5. Mi T M AW-4085-0016 Power Washer Pump Oil
Mi-T-M is another pressure washer manufacturer that makes its own brand of pump oil. This time, we have a natural, petroleum-based bottle of pump oil that will keep your pressure washer pump happy and healthy for a long time.
This oil comes in hard plastic, black bottle that holds 16 fluid ounces of liquid inside of it. On the side, you can see a graduated see-through strip that will reduce waste and help you use your oil in a calculated manner, always knowing how much you poured in and how much you have left.
The AW-4085-0016 is a specially formulated pressure washer pump oil. Its viscosity is not labeled on the bottle, but the corresponding Material Safety Data Sheet states that the viscosity of this petroleum-based hydraulic oil is cSt 9.2 at 100 degrees Celsius, which translates to SAE 15W20 oil viscosity.
When it comes to additives, your pump will be gently maintained with this oil’s EP protection, oxidation and corrosion resistance, and moisture dispersion.
6. General Pump 758-115 Pressure Washer Pump Oil Black
Next up, we have a Series 100 specially formulated pressure washer pump oil made by General Pump. If you’re looking to buy high-quality pump oil in bulk, we highly recommend this deal – here, you get 6 bottles, each containing 16 fluid ounces of oil.
This hydraulic oil comes packaged in a standard black plastic bottle that has a see-through slit on the side. This will help you pour oil with precision, without wasting a drop, and always know how much you have left in the bottle. Given that this is a pack of six, it will also help you keep track of which bottle you’ve used and how much you have left.
This natural petroleum-based oil is recommended for use in General Pump products that need less than 25 BHP. Its viscosity measures 100 cSt at 40 degrees Celsius, which roughly translates to SAE 30. That means it can be used in many pressure washer pumps out there.
You can find more information here.
7. Mag 1 60694-6PK Pressure Washer Pump Oil – 1 Quart Pack of 6
If you’re in search of a really good deal, we highly recommend this six-pack of MAG 1 pressure washer pump oil. It comes at an incredible price for the volume, yet it’s a fairly high-quality pump oil that will keep your pump purring like a kitten without ever overheating.
This natural oil is made out of conventional petroleum stock. Its viscosity is rated SAE 30W, and as such, it can be used in most commercially available pressure washer models. The fluid is enriched with additives which will keep your pressure washer pump well-maintained. Among these are additives that prevent foaming and aeration, protect against oxidation and rust, and some that prevent the formation of sludge.
This deal is seriously good – for a very low price you get six bottles, and each contains 1 quart of liquid. That’s a total of 1 1/2 gallons of pump oil – enough to keep your pump well-lubricated for years. The oil comes in a sturdy bottle that has an ergonomic design to help you grasp and hold it with ease.
You can access the oil’s performance information here.
Pressure Washer Pump Oil Buying Guide
Getting the right pressure washer pump oil is not too difficult. However, if you pick the wrong one, you can cause irreparable damage to the pump of your pressure washer. The likely result of using the wrong type of oil is a necessary pressure washer pump replacement. Because of that, you should find out what the best type of oil for your pressure washer is, and get that specific type of oil. Here are some important tidbits you should know before you go oil shopping.
1. Manufacturer Recommendation
The first thing you should check is whether the manufacturer of your pressure washer has a pump oil recommendation. The first step in an oil change should be checking the user manual or the manufacturer’s website for the proper type of oil.
Some manufacturers even make and sell their own oils that are developed to completely match the design of the pumps they use in their pressure washers. Others simply recommend the type of oil that suits the pump well.
Don’t skip this step. There are many kinds of oil out there and the wrong type can cause damage to your pressure washer pump, making costly replacements necessary. It’s better to be safe than sorry.
2. Non-Detergent Oil
The single most important distinction between regular motor oil and oil designed for pressure washer pumps is that regular oil often contains detergents. The role of detergents is to pick up contaminants as it flows through the engine and bring them to the oil filter, keeping the engine clean. However, water pumps don’t have an oil filter, making this procedure downright dangerous. You simply don’t want these contaminants flowing through your pump over and over again – it can quickly wear the pump off.
In fact, you should always look for the designation ND – which stands for Non-Detergent when getting pump oil. These usually also contain anti-foaming and anti-aerating additives, which prevents the formation of bubbles inside the pump. Foam bubbles can cause serious damage in the form of cavitation, which can damage the pump. As you can imagine, oils with detergents tend to foam up a lot, which doesn’t harm a regular car engine but can be deadly for your pressure washer pump.
When looking for pump oil you’ll notice that there is a specific system of codes that label these oils. So, you might see something like SAE 10W-30. To understand what this means, we need to discuss viscosity.
The simplest (though informal and incomplete) way to describe viscosity is as “thickness” of a liquid. You already know that peanut butter is thicker than syrup, and syrup is thicker than water. However, the thickness of peanut butter changes depending on the temperature, and it flows much better (gets “thinner”) when it’s hot, and seems icy-still when right out of the refrigerator.
In essence, the SAE designation tells you how viscose the oil is, or how easily it will flow through the pump. If there are two numbers separated with the letter W, you get the viscosity in both cold and hot environments. So, in SAE 10W-30, in winter (W) the viscosity is 10, and it rises up to 30 in warm temperatures. The higher the number, the “thinner” the oil is.
When it comes to hydraulic oil, these will be graded on the ISO scale, but they tell you the same thing. ISO 32 translates to SAE 10W, ISO 46 and 68 are approximately the same as SAE 20, and ISO 100 is equivalent to SAE 30. When it comes to gear oil, things can get confusing: SAE 75W-90 gear oil is about the same viscosity as SAE 10W-40 engine oil, so the distinction between oil types is important.
Most pressure washer pumps use SAE 10W-30 or SAE 10W-40 oil. However, you should always check the manufacturer’s recommendation for pump oil, and avoid using your pressure washer on freezing-cold winter days and the hottest days of the year.
Most pump oils come enriched with specific additives that make them even more helpful for keeping your pressure washer pump in its top condition. The most common additives in pressure washer oils are anti-rust additives that prevent corrosion, and anti-foaming and anti-aeration additives that control the amount of air in the pump. As we mentioned before, pump oil must not contain detergents that are present in regular car engine oil because pumps don’t come with a filter.
How to Change Pressure Washer Pump Oil?
Changing your pressure washer pump oil will ensure it lasts a long time and works with no issues. It’s a rather simple task, and it should take you about an hour to do it together with unmounting and mounting the pump back on the frame.
1. When to Change Pump Oil
The first time you change the oil in your new pressure washer is after the first 50 hours of use. After that, you should change the oil every 100 hours of work, or every 3 months – depending on what comes sooner.
Most triplex pumps come with a sight glass – generally a circle with a dot which shows how much oil should be there. If you notice that the oil level is under the dot, your pump needs more oil – but it’s much safer to drain and pour new oil than to merely add a bit. If your pressure pump doesn’t have a sight glass, check if it has a dipstick, or if the user manual recommends a particular amount of oil you should pour into your pump.
You should also change the oil if it’s leaking (of course, after detecting and repairing the problem), or if it’s a milky color.
2. What You Need to Change Pump Oil
- Oil catch – a tray or bowl to drain the oil in
- Wrench – to loosen up the bolt access. Not necessary if your pump has a plastic access knob
- Funnel – to avoid spilling when pouring oil
- Appropriate pressure washer pump oil
3. Steps to Changing Pump Oil
- Remove the pump assembly (usually together with the motor) and set it up on your workstation.
- Detect all bolts that you’ll need to use. You should have a drain bolt and a top access bolt. However, some pumps only have one.
- Remove the top access bolt so that the air pressure inside is relieved.
- Set up your oil catch under the pump’s drain access, and open it. Let all the oil flow out, and shift the position of the pump to make sure everything comes out.
- Put the drain bolt back and tighten it.
- Get your funnel and pour the pump oil through the top access. The reservoir shouldn’t be completely full. If your pump has a sight glass, make sure the level matches the dot. If not, check your user manual to find the specific amount it needs. Most pumps need approximately 12 fluid ounces of oil to work properly. Make sure you don’t overfill the reservoir, but also that you pour enough oil.
- Place the top access bolt back and tighten it.
- Mount the assembly back on your pressure washer after cleaning up any spillage.
FAQ About Pressure Washer Pump Oils
1. How should I dispose of used pump oil?
Recycling used oil is the most productive way to get rid of it, as it saves this valuable resource. Oil doesn’t really wear out, and it only needs to be cleaned with professional tools to be ready to use again. In fact, according to the EPA, to produce 2.5 quarts of lubricating oil you need either one gallon of used oil or as much as 42 gallons of crude oil.
After you catch all the drained oil on your oil catch, pour it into an empty bottle, and bring it to a recycler. Most local car mechanic shops and recycling centers will accept it. If you don’t have any nearby, try Jiffy Lube or similar. If there aren’t any near your place, you can even check if your local big supermarket accepts used oil.
If you can’t find any of those, you should call your local dump to check if they accept used oil, since many do. However, this is the least eco-friendly option, as oil that ends up in the soil and local bodies of water can seriously harm wildlife in your area.
2. What is the difference between synthetic and natural oil?
In your search for pressure washer pump oil, you might have to pick between conventional natural oil and synthetic oil. Let us tell you right away that you can use either of these and your pump will do just fine – but there are still some differences between them.
Synthetic oil is much harder to make, but its quality and purity are overall much higher. That’s because the manufacturer has total control over every aspect of the product down to the molecular level. In general, synthetic oils have somewhat better performance and longer durability as it doesn’t get dirty as fast. However, that also means that synthetic oil is much more expensive. The choice between the two is entirely up to you – with a regular oil change schedule, conventional oil will do just as well as synthetic.
There you have it, that’s all the most important information you need about choosing the best pressure washer pump oil for your machine. You use your pressure washer to maintain your garage, yard, house, and work tools in their best shape, but doing regular maintenance is imperative for helping the machine keep its peak performance. Changing your pressure washer oil is only one of the important tasks you should do, but it’s easy and simple enough: You just need a bottle of well-fitting oil and a bit of time every 3 months to do it right.
We hope we answered all of the questions you had in our guide, and that you found a great oil for your pressure washer among our reviews. However, if you have any questions left, please don’t hesitate to leave a comment below, and we’ll get back to you as soon as possible!