I have a Karcher K5.55M The motor pulses and only 1/2 pressure

It sounds like there may be a potential issue with the pressure build-up mechanism in your Karcher K2 compact. The constant motor running without water pressure could indicate a problem with the pump or the pressure switch. I would recommend checking the following:

1. Check the inlet filter: Ensure that the inlet filter is clean and free from any debris or blockages. A clogged filter can restrict water flow and affect pressure.

2. Inspect the nozzle: Make sure the nozzle is not obstructed or damaged. A blocked or damaged nozzle can restrict water flow and affect pressure as well.

3. Check the pressure switch: The pressure switch is responsible for regulating the motor and water flow. It's possible that the switch is faulty or not functioning correctly. Consider contacting Karcher customer support or a professional technician for assistance with checking and possibly replacing the pressure switch.

4. Examine the pump: There might be an issue with the pump itself. It could be worn out, clogged, or experiencing other internal problems. In such cases, it's best to reach out to Karcher customer support or a professional technician for further diagnosis and repair.

Remember to always follow safety precautions and consult the user manual provided by Karcher for specific troubleshooting steps and guidelines.

My account pin on 0711825797

This fault is within the control head, under the detergent valve is a small spring loaded valve that acts to induce the detergent, this will have failed, the shaft of the component breaks off the disk base leaving a small hole in the centre of the disk. This is enough to allow pressure past the component. The machine will pulse when operated and will not induce the detergent. I've looked everywhere to find this part as I have a karcher with the same fault.

There should be a pressure regulator somewhere in the pump, check your owners manual or go on mfg. Site and see if you can find your model.

this Karcher unit have a termal overload in the motor but your problem can be cause by a pressure switch the shutt on and off the motor when you stop spraying.

Is liquid leaking from the base, when the Pressure washer is on ?
I have the same Problem, the leak is from the seam of the Manifold housing. There is a small crack in the seam. A manufacturing defect.. A New Manifold Complete Replacement is $61.03, about the half the price what I paid for this pressure washer at Walmart... :( If under 1 year old, and you can find a receipt,Karcher will replace the whole Pressure washer under warranty.

You did winterize the machine? Leaving water in a powerwasher will freeze and damage the pump. It's a common happening, because people don't think of it or are not told by the maker.

replace the fuel carburetor filter and, or, your fuel tank filter

Hi, I had the same problem, Replaced the O rings and the rubber seals and cups inside the pressure washer and eventually the hose itself burst. Turns out the hose was leaking, internally between the inner sheath and the outside plastic cover, for quite some time and this caused the pulse. New hose and pressure cleaner is as good as new.

I had the same problem,and I replace the spare part set control head parts,Same problem when it goes hum hum,if you look inside it with a magnified glass you`ll be able to see hair crack line.