Specifications

118 5975 Series MSD Troubleshooting and Maintenance Manual
4 General Maintenance
To Lubricate the Side Plate O-Ring
Materials needed
• Cloths, clean (05980-60051)
• Gloves, clean, lint-free
• Large (8650-0030)
• Small (8650-0029)
• Grease, Apiezon L, high vacuum (6040-0289)
The side plate O-ring needs a thin coat of grease to ensure a good vacuum seal.
If the side plate O-ring appears dry or does not seal correctly, lubricate it using
this procedure. A good test is to wipe off the side plate with methanol, then
close the analyzer chamber. If the O-ring has enough grease on it, it will leave a
faint trace on the side plate.
Procedure
1 Vent the MSD.
2 Open the analyzer chamber.
3 Use a clean, lint-free cloth or glove to spread a thin coat of high vacuum
grease only on the exposed surface of the O-ring (Figure 15).
4 Use a clean, lint-free cloth or glove to wipe away excess grease. If the
O-ring looks shiny, there is too much grease on it.
5 Close the analyzer chamber.
6 Pump down the MSD.
CAUTION
Vacuum seals other than the side plate O-ring and vent valve O-ring do not need to be
lubricated. Lubricating other seals can interfere with their correct function.

CAUTION
Do not use anything except the recommended vacuum grease. Excess grease can trap
air and dirt. Grease on surfaces of the O-ring other than the exposed surface can trap
air, resulting in air spikes during operation.