HP 5890 Series II Plus Reference Manual page 167

Preventive Maintenance
Split/splitless capillary inlets
Use leak detection fluid to check for leakage at the column nut. If
leakage is observed, try tightening the nut first. If leakage continues,
replace the ferrule.
Note that if the inlet is hot, leak detection fluid may boil, giving false
indication of a leak.
If the septum and column nut prove to be leak•free,replace the seal
(O•ring)on the inlet insert.
Repressurize the system and check again for overall system
leak•down.
Figure 8-6
Location of the Split/Splitless Capillary Inlet Solenoid Valve
Flow Module:
Split/Splitless
Capillary Inlet
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