Specifications

112 5975 Series MSD Troubleshooting and Maintenance Manual
4 General Maintenance
To Remove the EI Calibration and Vent Valve Assembly
Materials needed
• Screwdriver, Torx T-15 (8710-1622)
Procedure
1 Vent the MSD.
2 Trace the calibration valve cable to the connector next to the fan and
disconnect it.
3 Loosen the collar and remove the calibration vial (Figure 13). Just loosen
the collar, do not remove it.
4 Remove the two screws holding the valve assembly to the top of the
analyzer chamber. Do not lose the O-ring under it.

CAUTION
Removing the valve with the vial installed can result in liquid calibrant getting into the
restrictor of the valve. Liquid in the restrictor will prevent diffusion of PFTBA into the
analyzer chamber for tuning. Replace the valve if this happens.