DeWalt pressure washer

[StarTech]

 

[PTmowerMech]

145 is the soap injector. 131 is the over pressure relief valve. It blows out to protect the pump. 104 is the unloader and 91 is the pressure regulator.
You have a blockage in the system somewhere at the pump outlet

The pressure release valve didn't release any pressure.

 

[Hammermechanicman]

You need to take the entire assy off the pressure washer and figure out what is blocked.
How it works: water in the inlet, goes into pump and pressurized, comes out of pump. Goes onto the unloader assy. If trigger pulled the water comes out the hose and wand. Release the trigger and pressure builds till unloader opens and water is just recirculated back through the pump. As water is recirculating in the pump it is getting hotter and hotter. At some point the water boils and the pressure goes high enough to blow the over pressure/thermal relief valve. Some are self resetting and some blow out requiring a new valve. Some screw into the side of the pump and some are in the outlet assy. The better pumps have it screwed into the pump body.
If you release the trigger and it kills the engine that usually means the unloader is stuck, corroded, rusted. On some pressure washers the pressure regulator and unloader are made together. Some they are separate. Take some pics.

 

[PTmowerMech]

 

[PTmowerMech]

You need to take the entire assy off the pressure washer and figure out what is blocked.
How it works: water in the inlet, goes into pump and pressurized, comes out of pump. Goes onto the unloader assy. If trigger pulled the water comes out the hose and wand. Release the trigger and pressure builds till unloader opens and water is just recirculated back through the pump. As water is recirculating in the pump it is getting hotter and hotter. At some point the water boils and the pressure goes high enough to blow the over pressure/thermal relief valve. Some are self resetting and some blow out requiring a new valve. Some screw into the side of the pump and some are in the outlet assy. The better pumps have it screwed into the pump body.
If you release the trigger and it kills the engine that usually means the unloader is stuck, corroded, rusted. On some pressure washers the pressure regulator and unloader are made together. Some they are separate. Take some pics.

Here's a video of the unloader. Seems free to me.

 

[Hammermechanicman]

The shiny brass thing below the unloader and 90 degrees to it is the thermal/overpressure valve and looks to be intact. The unloader takes hundreds of pounds of pressure to activate it to go into bypass.

 

[PTmowerMech]

The shiny brass thing below the unloader and 90 degrees to it is the thermal/overpressure valve and looks to be intact. The unloader takes hundreds of pounds of pressure to activate it to go into bypass.

So what little I was pushing on it, wasn't enough to know if the unloader is working?

 

[ILENGINE]

So what little I was pushing on it, wasn't enough to know if the unloader is working?

This is not how the unloader works. That part in the video that you are pushing free floats to create a cushion on the valve that opens. the unloader works by pushing high pressure water into the brass part below the big spring, which is turn actually compresses the big spring to open the valve. If it is working correctly on a pressure washer you can see it compress the spring when you let go of the trigger. There are O rings up inside of that brass parts that screws in the pressure washer head which is was is referred to as item 104 on your parts diagram

If you remove the nuts holding the big spring on and then push that down there are a lot of parts in that brass threaded piece.

 

[StarTech]

Lane since apparently you are ignoring my PMs from PPETEN, I have deleted them as apparently you are not needing the IPL for this pump, the primer on pressure washers pumps, or even the info on the drag link that you asked for.