Kärcher HD 6/16-4 M / MX User manual

English 5.906-246.0 Rev. 01 (09/14) 1
HD 6/16-4 M / MX
HD 7/18-4 M / MX
HD 9/19 M / MX
HD 9/20-4 M / MX
Service Manual

2 English 5.906-246.0 Rev. 01 (09/14)
1 Contents
2 Preface 3
3 Safety instructions 3
3.1 Hazard levels 3
4 Technical Features 4
4.1 Drive 4
4.2 Pump 4
4.3 Detergent system 4
4.4 Electrical system 4
4.5 Other features 5
4.6 Field of application 5
4.7 Type plate 5
5 Parts of the system 6
5.1 Front view 6
5.1.1 M-device 6
5.1.2 MX-device 6
5.2 Rear view 7
5.3 Bottom view 8
5.3.1 Pump head HD 6/16, HD 9/20 8
5.3.2 Pump head HD 7/18, HD 9/19 8
5.4 Front view (without cover) 9
5.5 Front view (electric box opened) 9
5.5.1 1-phase device 9
5.5.2 3-phase device 10
6 Function 11
6.1 Motor/pump unit 11
6.2 Pump head 12
6.2.1 Versions 12
6.2.2 High pressure seal / low pressure seal 13
6.3 Pump diagram 14
6.3.1 HD 6/16-4, HD 9/20-4 14
6.3.2 HD 7/18-4, HD 9/19 17
6.4 Hand spraygun 20
6.5 Pressure and volume regulation 21
6.6 Triple nozzle 22
7 Basic settings and service procedures 23
7.1 Adjusting the overflow valve 23
7.1.1 Trigger gun with servopress pressure regulator 23
7.1.2 Trigger gun standard 23
8 Care and maintenance 23
9 Troubleshooting 24
10 Technical Documentation 25
10.1 Technical specifications 25
11 Special tools 27
12 Circuit diagram 29
13 Torques 32

English 5.906-246.0 Rev. 01 (09/14) 3
Good service work requires extensive and practice-orient-
ed training as well as well-structured training materials.
Hence we offer regular basic and advanced training pro-
grammes covering the entire product range for all service
engineers.
In addition to this, we also prepare service manuals for im-
portant appliances - these can be initially used as instruc-
tion guides and later on as reference guides.
Apart from this, we also regular information about product
enhancements and their servicing.
If you should require supplements, have corrections or
questions regarding this document, please address these
citing the following subject to:
[email protected]
The responsible product specialist will take care of your is-
sue.
Copying and duplication of texts and diagrams as well
as third-party access to this information is permitted
only with the explicit permission of the company:
Alfred Kärcher GmbH & Co. KG
P O Box 160
D -71349 Winnenden
www.kaercher.com
Service and maintenance tasks may only be performed by
qualified and specially trained specialists.
Observe safety information in the chapters!
DANGER
Prior to all work on the appliance, switch off the appliance
and pull the power plug.
Shut off water supply.
Drain off water pressure.
DANGER
Foranimmediatedangerwhichcanleadtosevereinjuries
or death.
몇WARNING
For a possibly dangerous situation which could lead to se-
vere injuries or death.
몇CAUTION
Forapossiblydangeroussituation whichcanlead tominor
injuries or property damage.
ATTENTION
Pointer to a possibly dangerous situation, which can lead
to property damage.
Note
Indicates useful tips and important information.
2 Preface
Subject: Fall 118357
3 Safety instructions
3.1 Hazard levels

4 English 5.906-246.0 Rev. 01 (09/14)
These devices are the new top models among the mobile
high-pressure cleaners of the mid-range. Their compact
andverticaldesignallowseasyhandlingandspace-saving
storage.
Note
HD 7/18-4 M/MX
Pressure switch control with 2-phase switching.
–3 piston axial pump with stainless steel piston
–Piston with ceramic coating, with HD 9/20 only
–Cylinder head and water inlet made of brass
–High-pressure and suction valves made of stainless
steel
–Direct shutoff with closed gun via pressure switch con-
trol
–Overflow valve for pressure and quantity regulation
–Control injector
–Pressure holding valve
–Manometer
–Detergent injector
–Detergent check valve
–Switch CHEM system, continuously adjustable 2-way
dosing valve at the back of the device.
–Power switch with overload protection
–Pressure switch control
Note
HD 7/18 devices only
–Pressure switch control with 2-phase switching
4 Technical Features
4.1 Drive
4-pin, electro mo-
tor Cooling rpm Voltage/cur- rent type
HD 6/16-4 M/MX Air-cooled 1400 230 V / 1~ /
50 Hz
HD 7/18-4 M/MX Air-cooled 1400 400 V / 3~ /
50 Hz
HD 9/20-4 M/MX Water-cooled 1400 400 V / 3~ /
50 Hz
2-pin, electro mo-
tor Cooling rpm Voltage/cur- rent type
HD 9/19 M/MX Air-cooled 2800 400 V / 3~ /
50 Hz
4.2 Pump
Device Piston diam-
eter in mm Special features
HD 6/16-4 M/MX 16 Piston with piston
domes
HD 7/18-4 M/MX 18 Piston with piston
domes
HD 9/19 M/MX 16 Piston with piston
domes
HD 9/20-4 M/MX 20 Piston with piston
shoes
4.3 Detergent system
4.4 Electrical system

English 5.906-246.0 Rev. 01 (09/14) 5
–Softgrip-Easypress gun with improved ergonomics
–Highest operating comfort thanks to improved, continu-
ous pressure and water volume regulation
–Servopress rotary regulator with ceramic insert
–Improved mobility on stairs thanks to large full rubber
wheels (Ø 250mm)
–Easy oil level check from the outside, without removal
of the casing cover
This service manual describes the following appliances:
1.524-xxx
–HD 6/16-4 M
–HD 6/16-4 MX
–HD 7/18-4 M
–HD 7/18-4 MX
–HD 9/19 MX
–HD 9/19 M
–HD 9/20-4 M
–HD 9/20-4 MX
The type plate is located on the right side of the appliance.
1 Appliance description
2 Connected load
3 Part number
4 Type of protection
5 Year of manufacture
6 Serial number
7 Nozzle size
8 Address of manufacturer
9 Bar code. Contains part and serial number.
10 Max. feed temperature
11 Typical operating weight
12 Max. operating over-pressure
13 Working pressure
14 Flow rate
15 Main Supply
4.5 Other features
4.6 Field of application
4.7 Type plate

6 English 5.906-246.0 Rev. 01 (09/14)
1 Lock trigger gun
2 Lever for trigger gun
3 Trigger gun
4 Power press regulator
Pressure/ quantity regulation
5 High pressure hose
6 Spray lance
7 Mains cable with mains plug
3-phase appliances
8 Mains cable with mains plug
1-phase appliances
9 Nozzle
10 High pressure connection
11 Water connection
12 Manometer
13 Oil level indicator
14 Cover
15 Power switch
16 Transport handle
17 Push handle
1 Lock trigger gun
2 Lever for trigger gun
3 Trigger gun
4 Power press regulator
Pressure/ quantity regulation
5 High pressure hose
6 Spray lance
7 Mains cable with mains plug
3-phase appliances
8 Mains cable with mains plug
1-phase appliances
9 Nozzle
10 Roller guide for high-pressure hose
11 Cap
12 Water connection
13 Manometer
14 Oil level indicator
15 Cover
16 Power switch
17 Transport handle
18 Hose drum
19 Push handle
5 Parts of the system
5.1 Front view
5.1.1 M-device
5.1.2 MX-device

English 5.906-246.0 Rev. 01 (09/14) 7
1 Hose drum
2 Crank, hose drum
3 High pressure hose
4 Detergent
5 Storage mains connection, compartment for replace-
ment nozzle
6 Connection 2
Detergent
7 Bottle holder for detergent
8 Connection 1
Detergent
9 Dosage valve for detergent
Switch-over from detergent bottle 1 to 2
10 Storage, trigger gun with spray lance
11 HD...Plus includes a dirt remover as part of standard
delivery.
5.2 Rear view

8 English 5.906-246.0 Rev. 01 (09/14)
Note
The pressure switch is not adjustable.
Note
The pressure switch is not adjustable.
5.3 Bottom view
5.3.1 Pump head HD 6/16, HD 9/20 1 High pressure connection
2 Overflow valve
3 Pump head
4 Control piston, pressure
switch
5 Pressure switch Q2/B1
6 Water connection
5.3.2 Pump head HD 7/18, HD 9/19 1 High pressure connection
2 Overflow valve
3 Pump head
4 Control piston, pressure
switch
5 Pressure switch Q2
6 Water connection

English 5.906-246.0 Rev. 01 (09/14) 9
1 Electronics system
2 Detergent hose
3 Pump motor
4 Manometer
5 Detergent hose with check valve
6 Detergent injector
7 High pressure connection
8 High pressure line
9 Safety clip, high pressure line.
10 Overflow valve
11 Pump head
12 Connection for water supply with filter
13 Oil tank
14 Closing head
15 Power switch
HD 6/16-4
Version 1
5.4 Front view (without cover)
5.5 Front view (electric box opened)
5.5.1 1-phase device
1 Power switch Q1
2 Capacitors

10 English 5.906-246.0 Rev. 01 (09/14)
HD 6/16-4
Version 2
HD 7/18-4
HD 9/19
HD 9/20-4
1 Power switch Q1
2 Capacitors
5.5.2 3-phase device
1 Power switch Q1
2 Pressure switch
connection
1 Power switch Q1
2 Contactor K1

English 5.906-246.0 Rev. 01 (09/14) 11
1 Screw fan wheel attachment
2 Fan wheel
3 Motor bearing, rear (B bearing)
4 Motor casing
5 Motor shaft
6 Stator
7 Rotor
8 Shaft seal ring
9 Motor bearing, front (A bearing)
10 Oil bath
11 Fastening screw, swash plate
12 Holding plate of piston spring
13 Piston spring
14 Plunger
15 Oil seal
16 Low pressure seal
17 High pressure seal
18 Suction side pump
19 Suction valve
20 Control piston, pressure switch
21 Screw connections
22 Locking screw for pressure valve
23 Pressure valve
24 Manometer
25 Axial bearing
26 Swash plate
27 Fitting key
28 Engine mount
6 Function
6.1 Motor/pump unit

12 English 5.906-246.0 Rev. 01 (09/14)
1 Overflow valve
2 Detergent injector
3 Control pressure injector
4 Pressure holding valve
5 Pressure valves
6 Suction valves
7 Pump head
A Pump head old
B Pump head new
1 Pressure holding valve
6.2 Pump head
6.2.1 Versions

English 5.906-246.0 Rev. 01 (09/14) 13
Note
Pay attention to installation position of the seals. 1 Bushing
2 O ring
3 Disc
4 High pressure seal
5 Low pressure seal
6 Disc
1 High pressure seal
2 Disc
3 O ring
4 Bushing
5 Disc
6 Washer ring
7 Low pressure seal
8 Spreader ring
6.2.2 High pressure seal / low pressure seal

14 English 5.906-246.0 Rev. 01 (09/14)
Trigger gun and servopress rotary regulator opened:
When the power press regulator is opened all the way, the
water flows from the pressure room through the pressure
holding valve via the control pressure injector to the high
pressure outlet.
The ball of the overflow valve is pressed onto the valve
seat by the pump pressure and thus seals the connecting
boring to the suction chamber.
The manometer displays the working pressure in the pres-
sure room.
But, due to the affect of the control pressure injector, there
is less pressure in the connecting boring.
Servopress rotary regulator partially closed:
6.3 Pump diagram
6.3.1 HD 6/16-4, HD 9/20-4
1 Manometer
2 Pressure holding valve
3 Pressure room with pressure valves
4 Pressure switch Q2/B1
5 Connecting boring to overflow valve
6 Overflow valve ball
7 Connecting boring to suction room
8 Piston rod
9 Connecting boring from the overflow valve
to the control pressure injector
10 Detergent injector
11 High pressure outlet
12 Control pressure injector

English 5.906-246.0 Rev. 01 (09/14) 15
With the power press regulator partially closed, the pres-
sure in the pressure room will not rise any further. Howev-
er, due to less water volume, the effect of the control
pressure injector decreases, so that the pressure in the
connecting boring rises. Thus, the piston rod is pressed
slightly to the right against the spring pressure. The cone
tip of the rod slightly pushes the ball out of its seat so that
a part of the flow rate flows to the suction chamber.
The pressure switch is slightly pushed to the right due to
theincreasedpressureintheconnectingboring,butnotfar
enough to switch off the pressure switch.
1 Manometer
2 Pressure holding valve
3 Pressure room with pressure valves
4 Pressure switch Q2/B1
5 Connecting boring to overflow valve
6 Overflow valve ball
7 Connecting boring to suction room
8 Piston rod
9 Connecting boring from the overflow valve
to the control pressure injector
10 Detergent injector
11 High pressure outlet
12 Control pressure injector

16 English 5.906-246.0 Rev. 01 (09/14)
Trigger gun closed:
Upon closing the trigger gun, the pressure in the pressure
room rises abruptly. This pressure peak will affect the pis-
ton rod and the pressure switch via the connecting boring.
The ball is pressed out of its seat by the piston road and
the entire flow volume can flow to the suction room via the
connecting boring.
The pressure switch switches the motor off.
Assoon as thetriggergun is closed,thepressure retaining
valve closes. This way the entire system pressure is
locked between the trigger gun and the pressure retaining
valve.
When the gun is opened again, the pressure in the system
decreases rapidly, the overflow valve returns to its original
position and the pressure switch switches the motor back
on.
1 Manometer
2 Pressure holding valve
3 Pressure room with pressure valves
4 Pressure switch Q2/B1
5 Connecting boring to overflow valve
6 Overflow valve ball
7 Connecting boring to suction room
8 Piston rod
9 Connecting boring from the overflow valve
to the control pressure injector
10 Detergent injector
11 High pressure outlet
12 Control pressure injector

English 5.906-246.0 Rev. 01 (09/14) 17
Trigger gun and servopress rotary regulator opened:
When the power press regulator is opened all the way, the
water flows from the pressure room through the pressure
holding valve via the control pressure injector to the high
pressure outlet.
The ball of the overflow valve is pressed onto the valve
seat by the pump pressure and thus seals the connecting
boring to the suction chamber.
The manometer displays the working pressure in the pres-
sure room.
But, due to the affect of the control pressure injector, there
is less pressure in the connecting boring.
6.3.2 HD 7/18-4, HD 9/19
1 Manometer
2 Pressure holding valve
3 Pressure room with pressure valves
4 Pressure switch Q2
5 Connecting boring to overflow valve
6 Overflow valve ball
7 Connecting boring to suction room
8 Piston rod
9 Connecting boring from the overflow valve
to the control pressure injector
10 Detergent injector
11 High pressure outlet
12 Control pressure injector

18 English 5.906-246.0 Rev. 01 (09/14)
Servopress rotary regulator partially closed:
With the power press regulator partially closed, the pres-
sure in the pressure room will not rise any further. Howev-
er, due to less water volume, the effect of the control
pressure injector decreases, so that the pressure in the
connecting boring rises. Thus, the piston rod is pressed
slightly to the right against the spring pressure. The cone
tip of the rod slightly pushes the ball out of its seat so that
a part of the flow rate flows to the suction chamber.
The pressure switch is slightly pushed to the right due to
theincreasedpressureintheconnectingboring,butnotfar
enough to switch off the pressure switch.
Trigger gun closed:
1 Manometer
2 Pressure holding valve
3 Pressure room with pressure valves
4 Pressure switch Q2
5 Connecting boring to overflow valve
6 Overflow valve ball
7 Connecting boring to suction room
8 Piston rod
9 Connecting boring from the overflow valve
to the control pressure injector
10 Detergent injector
11 High pressure outlet
12 Control pressure injector

English 5.906-246.0 Rev. 01 (09/14) 19
Upon closing the trigger gun, the pressure in the pressure
room rises abruptly. This pressure peak will affect the pis-
ton rod and the pressure switch via the connecting boring.
The ball is pressed out of its seat by the piston road and
the entire flow volume can flow to the suction room via the
connecting boring.
The pressure switch switches off 2 of the 3 phases, this
way the motor is switched off.
Assoon as thetriggergun is closed,thepressure retaining
valve closes. This way the entire system pressure is
locked between the trigger gun and the pressure retaining
valve.
When the gun is opened again, the pressure in the system
decreases rapidly, the overflow valve returns to its original
position and the pressure switch switches the motor back
on.
1 Manometer
2 Pressure holding valve
3 Pressure room with pressure valves
4 Pressure switch Q2
5 Connecting boring to overflow valve
6 Overflow valve ball
7 Connecting boring to suction room
8 Piston rod
9 Connecting boring from the overflow valve
to the control pressure injector
10 Detergent injector
11 High pressure outlet
12 Control pressure injector

20 English 5.906-246.0 Rev. 01 (09/14)
1 Lock trigger gun
2 Casing shell
3 Hand lever
4 High pressure hose
5 Hose guide
6 Safety clip
7 Needle bearing
8 Coupling high-pressure hose/trigger gun
9 O ring
10 Node piece
Function
When the manual lever is actuated, the valve in the node
piece opens and the water can flow from the hose through
the gun into the spray lance.
Note
The node piece cannot be repaired and must be replaced
as a complete unit.
The date of manufacture is imprinted on the node piece. It
is composed of the month (letters A to L for January
through December) and year (1-digit number 1 for 2011, 2
for 2012, etc.).
Example: H1 = August 2011
6.4 Hand spraygun