If your pressure washer shuts off when the trigger is released, it has a problem with the unloader valve. There are a few issues with your unloading valve that causing stalling the engine pump. Troubleshooting of this problem is pretty simple and you can do it yourself easily.
We are going to discuss the troubleshooting procedure step by step. Keep reading the article to learn those steps.
Required Tools and Items:
- A screwdriver
- A wrench
Take a wrench and a screwdriver to unplug the unloader valve from its bay. First of all, unplug the valve retaining pin that locks the unloader valve with its bay. The retaining pin is something like a U-shape pin (common shape for most of the pressure washer). Insert your screwdriver inside the retaining pin and pull it up to unscrew the pin.
Now, use the screwdriver to pull the unloader valve from its bay. A gentle pull is enough to do that. One of the major parts of the unloader valve is its piston that controls the pressure retention. This piston moves forward and backward when you run the pressure washer. If the piston can’t move freely, your pressure washer shuts off. So, inspect the piston whether it is moving freely or has some issues to move.
If the piston is moving freely, skip this step and go to the next step. If your piston is not moving freely, you have to work on it. Unplug your piston from the unloader valve. Use your wrench to unscrew the nut that fastens the piston with the valve. Unplug the spring and piston from the unloader valve. Now, clean the spring and piston with alcohol or kerosene. After that, grease the spring and piston with good silicon grease. Now, set them back to their respective places. This will allow the spring and the piston work smoothly.
The unloader valve has a setting to produce pressure depending on your job. Check the valve setting to ensure it has a perfect setting. Maybe, your unloader valve has a too high setting that’s stacking the engine when the trigger is released. Your unloader valve must open up to cycle water back to the inlet side. When the valve fails to open up, it builds up high pressure that stalls the engine. So, adjust your unloader valve setting if required.
Sometimes, pressure washer shuts off due to the problem with the O-rings. Your unloader valve has O-rings that are generally known as washer or seal. If the O-rings are torn out, deteriorated, or in a poor state that is not enough to seal the oil pump, it may fail your unloader valve to work properly. Replace the O-rings with exact size ones. This will ensure proper sealing of the oil pump.
Inspect the pressure gun for its serviceability. If it is not in working condition, only adjusting the unloader valve may not bring the perfect result you are looking for. Adjust your pressure unloader valve and consider upgrading the gun as well.
If you have done with the abovementioned steps but the problem remains as it were, try the followings:
- Inspect and clean the air filter
- Clean the spark plug with alcohol
- Inspect the water inlet
- Inspect the wand screens
If everything is working fine but the problem remains, you can go for a local expert or consider buying a new unloader valve.
Using a machine with trouble kills your mental serenity and creates instability. Take care of your pressure washer so that it can care you in return. We hope that, this article on “pressure washer shuts off when trigger released” was a bit helpful for you.