I am a GCMS analyst for an Environmental lab that tests water and soils for volatile organic compounds. I recently changed the block on the back of my archon autosampler and now i have a helium leak on my soil purge needle. However the soil purge needle is not in use and should not be getting any He through it, let alone leaking. I attempted to remove the needle and cap it, but that did not work. we are still seeing a leak somewhere in the unit. any ideas on how this may be fixed?