Disassembly Procedure - Uwatec D420 Service Manual

Disassembly Procedure

1. Remove the mouthpiece clip or zip tie and the mouthpiece.
2. Lift the cover pin (48) from the case by using an
appropriate tool (e.g. 2.5 mm screwdriver), and then grasp
carefully with forceps and remove.
3. Using a thin-bladed knife, carefully lift the decal (36) from
the flow vane cap (35). Avoid scratching the flow vane
plug (35) beneath the decal.
4. Push the purge lever pin (45) out of the case with a pin
punch (MK2 HP seat tool) or 1.5mm hex key. Remove the
purge button (44) and spring (43) and set aside.
5. Unscrew the face plate (42), rotating counterclockwise
from the case. If necessary, use the SCUBAPRO D420
special tool PN 43.404.003 or a rubberized pad.
6. Carefully lift out the diaphragm thrust washer (41) and the
diaphragm (40).
7. By using the multi tool (function #9) or a face spanner
with a counterclockwise motion, unscrew the flow vane
plug (35) from the case.
8. The dive switch (33) and the flow vane washer (32) can
then be lifted out. O-ring (34) may fall out at this time.
9. Use a 3/32" Allen key to fully unscrew the small lever hex
screw (16) from the bottom of the housing (18). The lever
(37) will now be loose and it can be carefully removed.
10. Remove the decorative cap (11) from the case plug (10)
by carefully lifting with a brass spade or a flat blade
screwdriver.
11. Using a 6mm Allen key, unscrew the case plug. Use a
brass pick to carefully remove both o-rings.
12. Next, unscrew the hose inlet (5) with a 6mm Allen key and
pull it out from the housing support (8). As above,
carefully remove both o-rings (6).
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