What Causes A Pressure Washer To Lose Pressure?
If you're having issues with no or low pressure, especially after the pump has been sitting unused for a period of time, then the unloader pin or check ball is probably the cause. Typically, when a pump loses pressure, there is corrosion on the check ball, seat, or plunger on the unloader.
Sometimes people try to use Simpson Pump saver and conditioner (88266) to clear the pump and get pressure back. This is not the intended use, as this product is meant to be used before the pump is stored or sits unused for a period of time. When used properly, pump saver prevents corrosion and therefore extends the life of your pump and the pump components. It will not revive the pump if it is too late and the check ball or pin is already corroded.
How Often Should I Be Using Pump Conditioner?
We suggest using a pump conditioner any time your pressure washer pump will not be used for more than 7 days. This might seem excessive, but it's a quick process that takes less than a minute, and can save you a lot of money.
We have a video on how to use pump saver that you can watch here.
How Do I know If I Need A New Unloader?
You'll know you need a new unloader when there is visible corrosion or debris on or around your steel ball or seat, or when the unloader plunger will not actuate. The plunger should be easy to push in with your finger.
Below is an example of a corroded unloader and seat. If your steel check ball is corroded, it will look similar, or even get stuck due to sediment on the ball.


How Do I Fix A Pressure Washer With Low Pressure?
If you discover corrosion like we have pictured above, then we recommend replacing the unloader, seat, and check ball. We have a blog post with step by step instructions on how to do this: How To Replace An Unloader With Seat.
We also have a YouTube video covering this topic as well, which can be seen here: https://www.youtube.com/watch?v=hjAGG9Emk54&t=1s
Do you have questions about your pressure washer repair? Leave a comment below!