Karcher K4 Pressure Washer - How to Open and Fix an Internal Leak

The output pressure from my Karcher K4 suddenly dropped and it didn’t automatically shut off when I released the trigger on the gun. I then noticed water streaming from the base of the unit.

This video details how to disassemble the unit, locate where the leak is coming from, fix it and reassemble.

In my case, the faulty part was a plastic elbow that connects to the top of the pump, part number: 9.013-355.0

https://amzn.to/3XBZFGr

I purchased a genuine replacement from Amazon for £6.95 (at the time of making this video).

The part number received was 9.038-458.0 which looked the same and fitted without issue. It may be that the original part number has been superseded if this issue was caused by a manufacturing defect.

Karcher also appear to produce a metal variant of this elbow (9.042-155.0), however I do not know if this part will fit a Karcher K4 pressure washer.

Chapters:
00:00 Introduction
00:10 The problem
00:36 Opening up the case
05:56 Identifying where the leak is coming from
06:25 Disassembly
11:01 Replacement part and reassembly
20:45 Testing
21:36 Correct order of disassembly