54
HDK-MT350_EN_06
Replacing pilot control unit Y3/Y4/Y5
► Depressurise the dryer and shut it
down (see page 35).
► Undo the nut (373) of solenoid
mounting.
► Energise the solenoid (370).
► Remove the core tube (316).
Slightly push the solenoid (370)
upwards to ensure the open-ended
spanner fits neatly.
► Remove the core tube with plunger
(327) completely.
► De-energise the solenoid.
Caution
: The solenoid armature is
pressed out of the end sleeve by the
spring force (332).
► Use flat-nose pliers to carefully pull
valve seat (301) out of the hole.
The pilot control unit Y3-Y5 has been
disassembled.
Pilot control unit Y3/Y4/Y5
► Proceed as follows to install a new pilot control unit Y3/Y4/Y5:
► Fit new, lightly greased O-ring (310) onto the end sleeve (316).
► Fit valve seat (301) into the hole and push in as far as it will go.
► Fit washer (334) in end sleeve (316).
► Insert compression spring (332) and pin (333) into solenoid armature.
► Insert solenoid armature (327) into end sleeve (316).
► Fit solenoid (370) on end sleeve (316) without the seals.
► Energise the solenoid (370).
► With the solenoid armature energised, screw the end sleeve into the
mounting hole and tighten (tightening torque 100
+5
Nm).
► De-energise the solenoid.
► Fit solenoid seal (369, 371).
► Screw nut (373 onto solenoid mounting and tighten (tightening torque 15
+3
Nm).
► Check that all screw connections are tight.
► If no other maintenance work is to be carried out: Restart the dryer (see
page 36).
