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K4 motor keeps running when trigger released

I replaced control valve due to leak caused by crack. After assembly there is no leak. But the motor doesn't stop when trigger release. I checked the valve that should operate the on/off switch and it seems okay. I don't know why it isn't being activated when I release trigger. Cylinder head maybe ? Many thanks Mark

By Mark Woodhouse - Leamington - 24 May 2016

Answer this Question (3 Answers)

  • Fixed it. Although I had fitted a control head which was recommended. It wasn't exactly the same. I've now fitted the exact head and functions as new. It's imperative that you get all the nos exact as original, There's a version 1 and 2, both different diameters, Karcher kindly sent me the PDF on my model. I was able to identify the appropriate part no. I'm now an expert at stripping down and assemble By MWM - Tayside scotland - 15 August 2017
  • That's exactly what's happened to mine after fitting a new pump and control head. The switch works because I have tested it. The new unit was not exactly the same, the soap nozzle dia insert was different. I've had it to bits abut 5 times. Still the same. I'm beginning to think the hole that lets the pressurised water through to push the plunger that operates the switch is maybe not large enough. I'm going to check dia against the old one next. Anyone have thoughts on that, By Mwm - Tayside Scotland - 04 August 2017
  • Chris from eSpares
    Chris at eSpares says...

    For information on your repair see our video: How to Diagnose Pressure Washer Pump Problems: http://www.espares.co.uk/advice/8/3266

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Genuine Pressure Washer Cylinder Head Stock Number: ES538413

Genuine spare part for select models of Karcher pressure washers

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