Kärcher HD 1090, Service Handbook

Page: 21 / 34

19
Troubleshooting and basic settings
Unit does not reach required pressure
Check seal of valves
Disassemble the pressure valves/suction valves
Vent the unit
Pump not vented
– Switch off the unit. With the gun open, open
the water inlet and wait until the water comes
out without any bubbles.
Pump takes in air
– Check all the seals of the water inlet hose
connection.
Pressure valves leaking
– Unscrew the screw plugs.
– Pull out the valves and check for damage and
dirt. Replace if necessary.
– Mount all O-rings using silicone grease.
– Mount all screw plugs, noting the torque (see
technical data).
Suction valve leaking
– Remove the suction cover.
– Pull out the valves and check for damage and
dirt. Replace if necessary.
– Mount all O-rings using silicone grease.
– Install the suction cover, noting the torque
(see technical data).
Check seal of valves
– Position the valves with the valve seat up-
wards and fill with water. If the valves are
defective, the water will leak out underneath.
Replace valves if necessary.
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