Pressure Washing Equipment Sold by Professional Pressure Washers

How to Replace an Unloader on a Pressure Washer

What is an unloader?

Before we explain how to replace an unloader on a pressure washer, let’s break down exactly what an unloader is and does.

An unloader valve is part of the pressure washer that allows the pump to bypass the water flow back to the pump while you are using the spray gun. They act as a pressure regulator for the output pressure of your pump.

Step #1: How to replace an unloader on a pressure washer

Items needed:

2 crescent wrenches

A roll of teflon tape

Vice grips (something to hold it) or a pipe wrench

A pipe wrench

Unloader: Creates a new pressure on components of a pressure washing system, such as the holes, coil and pumps. Unloaders make sure the system doesn’t over pressurize and damage anything in the machine. It regulates the pressure and once it is set it should be left alone.

Step #2: Step by step instructions to take of the unloader

Take off the inlet from the pump by using a crescent wrench on each side of the fitting. Twist both of these off and set aside (It doesn’t matter which order it is taken off).

Next, you want to take off the bypass with a crescent wrench as well (or you could use a hose clamp to make it easier). Once the bypass is loosened, you should be able to use your hands to twist the hose off. If this doesn’t work then you will need a screwdriver to undo the clamp on the bypass. Once removed, set it aside so it doesn’t get anything else wet.

Bypass: Allows water to flow back through the system when the gun is not spraying. This prevents pressure build up in the system. Many machines just circulate the water back through the pump. If your system is feeding from a water tank then likely the bypass will dump the water back into the tank.

Now it’s time to take take off the out-line hose from the unloader (using two wrenches again to get each side of the fitting off). This part of the unloader is hooked up to your flow switch.

Now grab the unloader and either untwist it with your hand or use a wrench.

Step #3: Transferring the Bypass & Other Parts From the Old Unloader to the New Unloader

Make sure you have the old and the new unloader.

First, take off the bypass from the old unloader (just screw it off) and then hold the new unloader up in the same position as your old one so you know where you need to put the bypass on. Just screw the bypass on to the new unloader with your hands (make sure it is on tight).

Next step is to take off the plugs of the new unloader. Then grab your teflon tape and go clockwise around the plug you just took out. You only need wrap it around 1 ½ – 2 times. Now put the plug back where it was in the new unloader.

Now repeat step 3 with the other plug!

Next, take the fitting off the old unloader (with a wrench if needed). Now you discard the old unloader.

Place the teflon tape on the outlet fitting (1 ½ – 2 times around) and place it in the new unloader (use a wrench to tighten it). Make sure it is snug so it doesn’t leak.

Now your unloader is ready to be placed back on your pressure washing machine!

Now you are ready to install the new unloader!

how to replace an unloader on a pressure washer
How To Replace an Unloader on a Pressure Washer
How To Replace an Unloader on a Pressure Washer

how to replace an unloader on a pressure washer
How To Replace an Unloader on a Pressure Washer

Just take a look back at Step #2 on how to install in back in place.


Visit the rest of our site to view more pressure washing tips and tutorials.

If you currently live in Utah and are needing pressure washing repair and maintenance services, contact our sister company, AJET Services (801-330-0398 or

Contact Us

Social Media

Blog Post

Visit our pressure washing, janitorial, detailing and how to blog posts by visiting our “Tips & Tutorials” page.