Husqvarna DM 650 Workshop Manual page 20

11
20
Water valve
The water valve has a connection for the Gardena coup-
ling. To cool the motor, the machine must always be run
with water. The only exception is short test running in the
workshop without any load.
Filter
The hose coupling on the inlet side is fitted with a filter
that should be checked when servicing and cleaned, or
replaced if it is damaged.
A normal wood screw works excellently as a removal
tool. Screw the screw into the filter and pull this out.
Fit the filter by pressing it in on a flat surface.
Elbow couplers
Two elbow couplers are connected to the motor for the
cooling water supply. If these are removed they must be
replaced with new ones.
Fitting
The elbow couplers are taper-threaded and must not be
applied with any kind of sealant during assembly.
Screw in the couplers all the way by hand. Now tighten
with a tool one turn or more to align the connections as
shown in the image on the left. Note that the couplers
cannot be adjusted anti-clockwise during assembly as this
will lead to leaks.
Sealing unit
Two outer O-rings seal against the gear housing's gear box
cover and dual internal radial seals seal to the spindle
shaft (1).
There are holes in the plastic body between the seals that
connect with the channel that indicates leakage (2).
If water is leaking from the leakage channel, the radial seal
closest to the motor is defective. Oil leaks indicate that
the seal closest to the gear housing is defective.
Replacement
The sealing unit is replaced as a complete unit.
Remove the hose and the two screws (3). Pry off the
sealing unit with, for example, a pair of slip-joint pliers.
If this is not possible, the gear box cover must be
removed and the sealing unit pressed out from the
bearing side (4).
Check that the leakage channel is open by inserting a
steel wire.
Grease the two outer O-rings and the two inner radial
seals that seal to the spindle shaft. Also grease the spindle
shaft where it runs against radial seals. Use waterproof
grease.
Now press in the sealing unit and screw it in place.
Do not forget the guide washer!
Ensure that the guide washer (5) is in place before fitting
the sealing unit. The collar should be facing upwards.
(The guide washer centres the spindle shaft to prevent
damage to the radial seals, when the gear box cover is
fitted on the gear housing.)