Pressure hose will not stay attached to the karcher unit. The pressure builds in the unit and it blows out the hose from the main unit

SOURCE: Karcher Power Washer Problem

I had the same problem with my Karcher. The recall was lifted Aug. 0f 2007. Tried numerous people at Karcher....head of Customer Service, vice president, etc. No one returns telephone calls not even cutomer service....poor, very poor customer service. Thinking about calling Germany.

SOURCE: karcher k7.80 pressure washr

I have a Karcher K 3.86 M electric PW with a similar problem: water leaks from the pump near the outlet and the pressure surges on and off continuously at intervals of 1-2 seconds. The leak appears to be coming from a very thin crack in the plastic pump head in what I think is the "unloader" valve portion. I read elsewhere that if you leave water in these PW's and it freezes it will crack, causing leaks. I don't know how you can empty all the water out so I think we must store these PW's in areas that won't freeze in winter.

SOURCE: pressure washer won't build pressure

The problem sounds like its in the handle.. trigger mechinism

SOURCE: I have karcher 620m pressure

Try this. While pushing the trigger of the gun, turn lance fully anticlockwise and then turn back fully clockwise.

SOURCE: I have a Karcher Pressure

karcher K3.97 MB when connected up to tap and switched on pressure poor and motor seems slow cleaned hose end, and filter looks clean