HP 5973 - Page 143

4 Maintaining the MSD
To lubricate the vent valve O-ring
143
6 Reinstall the vent valve knob.
7 Pump down the MSD (page 58).
Vent valve O-ring
Vent valve knob
Front end plate
&$87,21
Be very careful when reinstalling the vent valve knob. It is very easy to cross thread the
knob and damage the threads in the front end plate. Be sure the O-ring stays in place.