I have modelled up these two parts to repair an old Lidl pressure washer.

this requires disassembly of the original pressure shut off switch by carefully pulling the actuator arm from the central pin (I compressed and zip tied the main spring to allow some free movement)

There is a replacement for the internal piston sleeve that had cracked which prevented the shut off from actuating, and for the outer main threaded cap which had failed and allowed water to flow out of the pump.