White milky oil in your pressure washer pump sight glass typically means one thing: contamination and water in the oil. While oil changes are a routine part of pressure washer maintenance, dealing with water-contaminated oil requires special attention. This post will cover why water might be in the oil, problems it can cause with your pressure washer pump, and how to change the contaminated oil to get your pressure washer running properly once more.
If water gets into the oil of a pump, it can cause a number of problems, including:
- Reduced lubrication: The water can dilute the oil and reduce its ability to lubricate the moving parts of the pump. This can lead to premature wear and tear on the pump.
- Corrosion: The water can corrode the metal parts of the pump. This can weaken the parts and make them more likely to fail.
- Foam formation: The water can cause the oil to foam and push out from your vent cap and seals. It can also reduce the ability of the oil to cool and lubricate the pump.
- Sludge formation: The water can react with the oil and other contaminants in the pump to form sludge. This sludge can clog the pump and prevent it from working properly.
How To Change Milky Pressure Washer Oil
1. Remove full pump from pressure washer
- Using basic hand tools, remove your pump from the pressure washer.
- We recommend having one or more rags ready in your workspace to set the pump on and help clean up any unwanted messes.
2. Remove oil plug and drain old oil
- Drain the largest amount of contaminated oil into an oil drain pan first.
3. Remove crankcase cover
- Drain the remaining oil into your oil drain pan to be discarded later.
- This can be taken to most Auto Zones where your oil was purchased.
4. Remove the sight glass
- First remove your oil sight glass from the pump and spray some WD-40 into the sight glass to remove any contaminated oil and residue from the sight glass cover assembly and use a rag to wipe off excess WD-40 after cleaning.
- Failure to remove the sight glass before using brake clean to flush the crankcase will result in damage to the sight glass.
5. Flush out the crankcase
- Use a non-chlorinated brake cleaner to completely flush out the crankcase.
- Be thorough: get in every tight spot and go over each spot a few times, this process typically requires 2 full cans of brake cleaner to complete.
- We use a non-chlorinated brake parts cleaner from our local auto parts store.
- DO NOT use this to clean the sight glass. It will cause discoloration and reduce visibility.
- Note: Always wear safety glasses, protective gloves and mask when using this product.
6. Repair the pump
The most common cause of water in the oil is cracked or fractured ceramic pistons. Other common causes include:
- Worn high-pressure seals or gaskets
- Small Hairline cracks in the pump housing
- Condensation: when the pump is not running, water vapor in the air can condense on the cold surfaces of the pump, such as the cylinder walls.
If you are unsure about why there is water in your oil, you should have it checked by a qualified mechanic. They will be able to determine the source of the water and recommend the best course of action to fix the problem.
7. Replace the crankcase cover and sight glass
- Use a torque wrench to tighten the screws to the proper torque setting.
- Note: check your pressure washer manual for it's recommended torque setting.
8. Install the pump back on the pressure washer
- We like to do this before adding our oil because it makes it level for viewing in the sight glass.
- We also recommend cleaning the crankshaft of your engine and appling a small amount of anti-seize before installing the pump back on the power washer.
9. Add the oil
- Fill the crankcase slowly with the proper manufactures suggest oil allowing the oil to settle until the oil has reached halfway up the sight glass.
10. Test the pump
- Test your pressure washer for 5+ minutes and then let the pressure washer pump sit for another 15 minutes to verify the oil is back to its normal color and level and that no further repairs need to be made to your pressure washer pump.
Tips to Prevent Water From Getting Into the Oil In Your Pump
- Inspect the pump regularly for leaks. Check the seals and gaskets for signs of wear or damage.
- Keep the pump clean and dry. Wipe down the pump after each use and store it in a dry place.
- Use the right oil for your pump. The oil should be compatible with the type of pump and the conditions in which it will be used.
- Change the oil regularly. The frequency of oil changes will vary depending on the type of pump and the conditions in which it is used.
By following these tips, you can help prevent water from getting into the oil of your pump and extend its lifespan.