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Pressure Washer Oil Looks Milky

With your schedule cleared up, you’ve finally decided to give your car a nice, cool bath with your pressure washer. The machine is working fine, the water pressure’s right, and it’s also not making any unusual noise. You give the washer an oil check and find out that the oil level is perfect. You should have been satisfied by seeing this, but you realize the oil color to be strange just then. A milky, cloudy sort of oil mixture is observed. You might wonder how big of an issue this can be. If you aren’t familiar with the oil-related maintenance of pressure washers, we suggest that you give this article a read.

Witnessing a milky looking oil in your pressure washer often means that water has leaked through the oil seals, thus indicating faulty O-rings and oil seals. The milky color is the water mixing with the oil, thus forming a cloudy suspension. In regards to this problem, the article details the following points:

Pressure washer oil looks milky, what can it be:

  • Damaged oil seals due to which water has leaked into the pump casing
  • Excess humidity causing condensation of water within the oiled portion of the pump

Possible solutions to the problem are:

  • Replacing the faulty seals
  • Purchasing an oil seal kit

We recommend that you go through all the troubleshooting steps that will not only pinpoint your problem but will also provide you with the most concise and user-friendly set of instructions that can alleviate your problem.

Possible Causes:

1. Damaged Seals:

All pressure washer pumps are filled with a lubrication oil to reduce wear and tear and maximize machine parts’ performance. Sometimes, due to poor pump maintenance, the oils seals that prevent the oil from leaking out of the pump get worn out, and it is mandatory to replace them. Due to these damaged seals, water might mix with the oil, and thus, you might as well see a milky looking oil.

2. Excess Humidity:

It may sound unusual, but excessive humidity in the air may also result in water condensation in the pump’s oil casing, ultimately making the oil look milky. This is highly likely in situations when the pressure washer has not been in operation for a long time. If you’re using the washer frequently, then this humidity does not result in any pump issues.


• Disassembly of the pump:

Before any component in the pump is to be replaced, the pump needs to come off. So, let’s look at the step-step process:

  • Remove the casing: First, loosen up the screws and bolts at the exterior using a wrench. The exterior of the machine will now be taken off. Arrange the bolts in order so that the reassembly can be done without much trouble.
  • Remove the pump case: After that, the inside of the pump might get visible to you. Now you need to remove the Allen socket so that the pump case is taken off. To do this, take the wrench and loosen the socket.
  • Remove the valve: After the pump case is removed, the valve will be visible to you. Using forceps or scissors, remove the valve but make sure you don’t damage it.
  • Open the pump casing: Split the pump casing in half to reach the oil pump’s side of it. You can strike it with a hammer to get to that but ensure that the casing is not damaged.
  • The seals should be visible: After you split the casing into two, the seals will be visible to you.

• Replacing the worn-out seal:

Seals might get damaged due to insufficient maintenance. Sometimes, extreme weather conditions can also cause expansion or contraction, which might reduce the life of the component. You should check all the seals of your pump and look out for faulty looking seals.

• Using the right seal:

  • Check the model number: Check for your washer’s model number and find the proper seals recommended by the user’s manual. You should ensure that the dimensions are being correct.
  • Remove the screws: Afterward, use an Allen key to remove the screws at the back of your pump
  • Remove the brass ring: Next up, you need to remove the brass rings that enclose the seals with caution. You should do this carefully so that the brass ring isn’t damaged.
  • Check each seal: Now, examine each seal from the brass ring and check if any seal appears damaged. If it does, replace it with the new one.

• Addition of fresh oil:

After the seal has been renewed, add new oil to the pump. Make sure that the pump is upright when the oil is being added. Take caution that the oil is added to the right level. After the oil has been added, you should clean the milky looking oil lying on the pump with a cleaner (preferably a roof cleaner)

• Buying an oil seal kit:

It is advisable to purchase an oil seal kit for your model so that timely maintenance can be carried out. The oil seal kit contains seals of various dimensions.

Additional Steps:

Replacing or repairing:

Sometimes the affection for old seals might lead you to repair and use them instead of replacing them. The repair might save you a few bucks and give a perfect solution, but the time frame of this solution’s effectiveness is lesser than replacement.

Old parts or new:

The striping off part of the procedure is the same here as well. All parts are to be dealt with extreme care. Sometimes, older sockets and seals are a bit stuck, but it is never wise to apply large impacts. Repair concept is much used when the pressure washer is not very much, and the o rings are not entirely dead.

Use of re-sealers:

Re-sealers are available in the market. Depending on the size of the engine, different re-sealers can be used. If the wear and tear on rings are excessive, a thicker and sticker re-sealer is used. Re-sealer forms a protective layer around worn out o ring. The seep of oil is prevented, and o ring replacement is not required. One of the most commonly used re-sealer is AT-205. The repair of oil rings is a lesser skill requiring a way to fix the milkiness of oil.

Cylinder liner defects:

A rarer cause of milkiness in oil is due to crack present is water jackets present around in cylinder liner. This is not common, and if this is the root cause, it is much better to consult a professional repairer. Repairer would use overhauling and reboring of the cylinder liner. And cracks will be welded by a welder of high skill before refinishing the cylinder liner. In such cases, it is advisable to change the engine’s cylinder liner as the repair would never be strong, and the effect may damage other vital components.

Related Questions:

With all of these root causes explained and their solutions provided in detail, many questions may still arise. A few generic problems may occur in people’s minds, especially those who opt to find a milky oil solution themselves. These questions are answered here for a better explanation.

1. What type of oil does a pressure washer commonly use?

If you are using a gasoline-powered pressure washer, it’s relatively common to choose the right type of oil that serves a specific purpose. Listed below are the kind of oil pressure washers deal with mostly.

All-purpose engine oil:

All-purpose engine oils are often used in temperate environments and are typical of the type SAE30. They are recommended for temperatures above 40 oF. However, if temperatures drop below 40 oF, it is advised that you use 10W-30 oil to help your power washer start without difficulty.

Non-detergent pump oil:

The synthetic oils of Briggs & Stratton can come to mind when thinking about non-detergent pump oil. Some pressure washers can operate better with pump oil, but another oil you can try using is 30W non-detergent oil. Non-detergent oils are considered to be better because they were common before oil filters became widespread.

This ensures that the chemicals are allowed to stick to the pressure washer engine’s sidewalls, keeping dirty oil from degrading or impeding its functionality. Using any other form of oil in your pressure washer can cause sludge to build up.

2. How to remove if any frothy accumulations are formed?

Froth is formed after excessive oil consumption, and when the oil quality was already low, its life cycle had ended. Froth can be very easily removed by cleaning the crankcase with diesel. Mostly, this is the solution used.

3. What if rings are fine, and there are no apparent cracks in the cylinder liner?

In this case, it is advisable to check the emission color of exhaust as well. If emissions are colored, problems may exist in the head gasket, and replacing the head gasket is the solution to a situation in which milkiness of oil is a secondary problem.

Final Remarks:

Panic is not the only thing you can do after seeing milky oil in a pressure washer. This condition’s causes are clear now, and how these can be dealt with is discussed in detail. Having regular checkups can save the machine from a much more significant loss. Proper and timely repair and maintenance of all components involved is the key to be safe from such emergencies. Some specific problems can never be dealt with by a person himself and will require professional help. Nevertheless, one can certainly give his best to become as good as possible to eliminate such problems. Ensuring regular maintenance and care will save you from the hassle of a major issue and enhance the service life of your machine.