How To Use The Unloader Valve To Adjust The Pressure Of Your Pressure Washer

How To Use The Unloader Valve To Adjust The Pressure Of Your Pressure Washer

The pressure washer has several parts that work together to ensure optimal results. One of the best merits of the parts is that they are durable. Apart from their durability, each part has a unique function that ensures cleaning efficiency. For example, the unloader valve plays a crucial role in regulating the machine’s pressure. An essential aspect of the pressure washing machine is its pressure. Thus, learning how to adjust it is an incredible skill. Below is a simple guide on adjusting the pressure of your machine using the unloader valve.

1. Turn on the engine of your pressure washer

The first step in regulating pressure is to ensure that your engine runs. Ensure that before the load, it is at 3700 RPM and 3400 after.

2. Prepare the unloader valve

Take the nylon lock off the valve and close down the nozzle. Also, remove the spring and washer from the unloader valve. After removing it, you will see two lock nuts and a threaded piston. Use a wrench to lock the nuts. Then put three threads on the bottom and place the nut, spring, and washer back to their original position.

3. Clipping the pressure

The next step is also straightforward. Fix the pressure gauge between the high-pressure hose and the pressure washer pump. Ensure that you can see the gauge when you tighten the adjusting knob and trigger the gun.

4. Filter the air from the pressure washer

You can remove the air from the machine by turning the water on before starting the engine. Make sure that you wait until the water is coming out.

5. Tighten the pressure spring

Tighten the spring as you check on the pressure gauge. Also, make sure that you get to the maximum pressure when tightening the spring and with the gun trigger engaged. The pressure should not exceed 10% when you disengage the trigger. The best pressure level is between 6% and 9%. Pressure above 10% can damage your machine. Thus, it is above 10%, make sure to regulate the nuts. Adjust the spring, washer, and knob if it does not lower.

6. Break in the unloader

Turn on the gun trigger to break in the unloader valve. Repeat the process 20 times to ensure that the valve will not hang.

7. Replace the knob and spring of the pressure washer

Adjust the knob, spring, and washer and move the nuts on the rod till you get to the minimum spike when you release the trigger and maximum pressure with the trigger gun engaged. Then remove the knob, spring, and washer. Then use a wrench to tighten the nuts and replace the washer, spring, and knob. After that, fix the nylon lock on the piston’s top.

8. Adjust the pressure

Adjust the pressure by regulating the knob between the nylon top and two nuts when the trigger gun is on.


Manufacturers often refer to the unloader valve as the pressure washer machine’s pressure regulator. Regulating the valve ensures you can easily adjust the pressure of the machine. Furthermore, the adjusting steps are very easy.