Kärcher HD 6/16-4 M / MX

Questions and Answers

A
Andrew KellyJul 31, 2025
How to fix Kärcher Pressure Washer not building up pressure?
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  hernandezpatrickJul 31, 2025
  If your Kärcher Pressure Washer isn't building up pressure, try these steps: First, set the nozzle to "High pressure" and clean or replace the nozzle. Then, vent the appliance to remove any air within the system. Check the water supply level against the technical data and clean the sieve in the water connection. Also, examine all inlet pipes to the pump, and check the pressure and suction valves for leaks, replacing them if needed. Finally, inspect, adjust, or replace the overflow valve.
F
fingramAug 4, 2025
What to do if Kärcher HD 6/16-4 M / MX Pressure Washer turns on and off when hand spray gun is closed?
- A
  Allison JonesAug 4, 2025
  If your Kärcher Pressure Washer turns on and off while the hand spray gun is closed, the issue might stem from the system's tightness or pressure regulation. Check the trigger gun and the O-rings on the high-pressure hose for leaks, and replace them if necessary. Additionally, inspect, adjust, or replace the overflow valve, and check or replace the pressure retaining valve, as well as the pressure switch or control piston.
S
Sarah MartinAug 9, 2025
Why Kärcher Pressure Washer does not switch off when the hand-spray gun is closed?
- J
  Jeffery SmithAug 9, 2025
  If your Kärcher Pressure Washer doesn't switch off when the hand-spray gun is closed, it could be due to a pressure issue. Check, adjust, or replace the overflow valve. Also, inspect and replace the pressure retaining valve and the pressure switch. Finally, check or replace the pressure switch or control piston.
J
Joshua TorresAug 13, 2025
Why is my Kärcher HD 6/16-4 M / MX Pressure Washer not running?
- D
  David GarrettAug 13, 2025
  Your Kärcher Pressure Washer might not be running due to several reasons. First, check the connection cable for any damages. Also, ensure that the supply voltage is correct. If the engine is overheated, turn the device switch to "0" and let it cool off for at least 5 minutes. Finally, inspect and, if necessary, replace the appliance switch and the pressure switch.
R
ryanmichaelAug 17, 2025
How to fix Kärcher HD 6/16-4 M / MX Pressure Washer when detergent is not being sucked in?
- J
  Jon ChandlerAug 17, 2025
  If the detergent isn't being sucked into your Kärcher Pressure Washer, ensure the nozzle is set to "CHEM". Then, check and clean the detergent suction hose with its filter. Open or check and clean the detergent dosing valve. Also, inspect, clean, or replace the detergent check valve and the nozzle for detergent. Finally, replace the detergent injector if necessary.
D
Derek SmithAug 22, 2025
What causes Kärcher Pressure Washer pump to vibrate?
- C
  Christopher Jackson MDAug 22, 2025
  If your Kärcher Pressure Washer pump is vibrating, check the suction pipes for water and detergent, making sure they are leak-proof. Close the dosing valve for detergent to operate the machine without detergent. Also, vent the appliance.
S
Stephanie KnightAug 26, 2025
How to repair a leaky Kärcher HD 6/16-4 M / MX Pressure Washer pump?
- M
  Meghan NelsonAug 26, 2025
  If your Kärcher Pressure Washer pump is leaky, and you notice water leaking between the cylinder head and the piston casing, check and replace the high-pressure and low-pressure seals. If there are oil leaks between the cylinder head and the piston casing, replace the oil seals. Also, check and replace the piston if needed.

Summary

Preface

Safety instructions

Details important safety information, hazard levels, and precautions for service and maintenance tasks.

Technical Features

Drive

Specifies motor types, cooling, RPM, and voltage/current for different high-pressure cleaner models.

Pump

Outlines pump construction, piston type, cylinder head material, and valve details.

Detergent system

Describes the detergent injector, check valve, and adjustable 2-way dosing valve for chemical application.

Electrical system

Covers power switch, overload protection, and pressure switch control features, noting 2-phase switching.

Other features

Highlights ergonomic design, improved mobility, and convenient oil level checking.

Field of application

Lists the specific high-pressure cleaner models covered by this service manual.

Type plate

Explains the identification details found on the appliance's type plate, including serial and part numbers.

Parts of the system

Front view

Provides labeled diagrams of components visible on the front of M and MX device variants.

Rear view

Shows labeled components on the rear of M and MX models, including hose drum and detergent storage.

Bottom view

Details the pump head configurations specific to HD 6/16, HD 9/20, HD 7/18, and HD 9/19 models.

Function

Motor;pump unit

Explains the operation of the motor/pump assembly, detailing internal components and their arrangement.

Pump head

Describes the components of the pump head, including valves, injectors, and seals.

Pump diagram

Presents hydraulic diagrams illustrating water flow and pressure regulation for specific HD models.

Hand spraygun

Details the functionality and components of the hand spraygun, including the node piece and its manufacturing date.

Pressure and volume regulation

Explains the rotary regulator with ceramic discs for adjusting water flow and pressure levels.

Triple nozzle

Describes the adjustable triple nozzle and its three distinct spray pattern settings.

Basic settings and service procedures

Adjusting the overflow valve

Provides step-by-step guidance for adjusting the overflow valve for both servopress and standard trigger guns.

Care and maintenance

Troubleshooting

Technical Documentation

Technical specifications

Presents detailed technical data, including voltage, flow rate, working pressure, and dimensions for all models.

Special tools

Circuit diagram

Torques

Kärcher HD 6/16-4 M / MX Specifications

General

Flow Rate	240-560 l/h
Weight	52.9 kg
Dimensions (L x W x H)	467 x 407 x 1010 mm
Power Type	Electric
Max. inlet temperature	60 °C
Voltage	400 V
Frequency	50 Hz
Pressure	160 bar