How to remove the nylon high pressure piece from a Karcher high pressure water pump.

SOURCE: Karcher 520M wont operate at high pressure

The solution is very simple. All you have to do is change the spill valve.
This because the spill valve is not worth servicing. The actual problem is that the spill valve is leaking from its bottom-part seating. When you close the gun, the spill valve goes down, opens from the underside, and switches the electricity off. When you press the gun, the spill valve returns to normal, and if the underside does not close, you have low presure, because the water keeps circulating.
Regards,
MG. (Karcher service engineer).

SOURCE: my karcher pressure washer has lost its water power

I have the same problem. With mine I have to remove the tip that I am using then pull the trigger and then replace the tip and pull and pressure should return. I believe that one of my valves is sticking causing me to reprime the pump frequently. I am trying to clean or replace my valves to fix the problem.

I hope this helps.

SOURCE: Karcher K 2400 HH Pressure Washer no pressure

http://www.landanorthwest.com/documents/instructional/spill_valve_instructions.pdf

SOURCE: Australian Karcher 2.91 intermitant start

Under the top cover there is a micro switch that sometimes dislodges
This switch is for auto cut off when you release the trigger

SOURCE: Water is leaking from under the chrome piece

Plastic Pump Manifold is cracked.
Can be replace at a local Karcher Service Center, or if you are mechanically handy. Replacement Manifold Complete, is available from www.karcher.com.
If it is under 1 year old, and under warranty Karcher will replace if you have a Receipt proof of purchase.