Small Engines (Lawn Mowers, etc.): Karcher 395 electric power washer

Question
pressure is fine when running, electric motor works good, but recently will not shut off when it is turned on , it use to turn off when the trigger on the hose was released , turn back on when you needed pressure, now it just runs, hit the trigger , sprays fine , let go of trigger keeps running

Any ideas

Answer
There must be a pressure switch on the pump that makes contact with an electric switch.  I suspect the pressure switch has an o-ring or a plastic piston.  The o-ring may need to be lubricated.

There is a You Tube video showing the pump dis-assembly.  
http://www.youtube.com/watch?v=ysxsEE7-1-Q

Another good video:
http://www.youtube.com/watch?v=UFXSLOBL0Mg

Take a look at the videos and see if they help.

Eric