Correcting Leaks; Potential Leak Areas - Agilent Technologies 6890 Series Service Manual

270 Pneumatics Control Module
Leak testing the PCM
Caution
Aluminum bracket removed for
clarity, DO NOT completely
remove the bracket during
valve replacement.
Screws
Supply fitting
O-ring
Septum purge fitting
Figure 270-4

Correcting leaks

1. Use the electronic leak detector to check all areas of the PCM that are
potential sources of a leak.
2. Tighten any connections which are leaking and re-test.
Note If the pressure drop is now 0.05 psi/min or less, you can consider the interface
system leak–free.
3. If the interface still leaks, continue to check for and correct leaks.

Potential leak areas

Check the following areas when checking for leaks in the PCM.
• The capped purge vent
• Three O-rings behind the block where the pneumatic lines enter the PCM
• Two O-rings for each valve in the PCM
10 of 10
serviceable parts
PCM
Inlets
Agilent 6890 Gas Chromatograph Service Manual
Aluminum bracket
Jun 2001