This leak is located on cooled gas lead flanges and is mostly on east side flange. It's due to old aged seal and is going to be patched up just for a short time! It will be fixed properly in the next long shut down.
Please note a LN2 cold trap was connected during all the following stages.
Helium leak check result beofre patching is (units are torr.lit/sec):
One of the bolts were taken out and it was fully threaded with RTV on it. Technically, it's a poor practice to apply RTV as a sealant on fully threade bolts! So, these bolts(M8x40) are replaced with partially threaded ones.
Sep 27, 2012
East flange leak is fixed now temporarily at room temperature as described here:
After all, leak result is as following: