Do you have a problem with your Karcher pressure washer losing pressure? There is a good chance that you have a sticky unloader valve inside of your pump. We know that it can be frustratingtrying to deal with this issue but really can be an easy fix. There could also be some other symptoms that can indicate a sticky unloader, these might be:
1. Complete loss of pressure
2. Pressure on machine is cycling on and off
3. Machine only has the pressure the garden hose puts out
4. You have to take the nozzle off the machine and run the machine in order for the high pressure to kick back in
If you have a problem removing the unloader from the cylinder you are going to have to hook the machine up to a water supply and try to force the unloader out. Sometimes it might require that you fire the engine up to remove the unloader, if you have to do so make sure to have something to catch the unloader over top of the pump (rag, towel, bag, piece of wood). If the unloader continues to be stuck we recommend pouring vinegar into the cylinder and letting it sit for 3 or 4 hours with the garden hose and high pressure hose hooked up to the machine and then try the removal process again.