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29
2.4.2.9 Closing Optical Unit
To close the optical unit, perform the following procedure:
1. Turn the top cover upside down.
2. Make sure that the contact surfaces with the O-ring are clean and apply a light coat of
high quality neutral silicone grease.
3. Install a new greased O-ring in the groove located in the top cover.
NOTE:
Use a synthetic grease such as MOLYKOTE BG87 INERTA or MOLYKOTE BG88
INERTA.
4. Remove the pressure release screw.
5. Install the inner cover on top of the cover.
NOTE:
Align the inner pan mounting holes on the top cover holes.
6. Make sure the base assembly and top assembly are correctly positioned and that the
wires do not get damaged between both parts (top cover and base).
7. Press the inner cover of the inner pan assembly on the top cover and secure with the
countersunk screws. Apply a droplet of Loctite 222 to the last threads. Torque screws to
22
±
4 inch-pounds (2.5
±
0.5 N•m).
8. Check the watertightness of the assembly by replacing the pressure release screw with a
pressure test fixture. The leak path can then be located by submerging the assembly in a
tank of water while pressurizing using shop air pressure to a maximum of 20 psi. Refer to
“Testing for Leaks” on page 30.
Make sure the O-ring seal for the pressure release screw is in good condition and reinstall the
pressure release screw.
Figure 22:
Pressure
Release
Screw
Alignment Pin
Power Supply
Fast-on Connectors
Paper Barrier