(follow-up on previous mentions) 
Using a "feeler" gauge I measured the "gap" on the feed-through flange previously discussed which I was concerned may eventually leak due to (possible) bottomed-out flange screws.  The gap was 0.004".  These flange bolts seemed bottomed-out in their blind holes and I was concerned that I would strip the threads or break the screws if I continued to torque them -> knowing that we were venting anyway to fix the 2 x 10-7 torr*L/sec leaking triax feed-through, I went ahead and "stood on the wrench" and was able to close the 0.004" gap on this feed-through flange -> I leak tested this flange afterwards and it still didn't leak.  I don't know why this felt sooo... different than normal-perhaps the gasket was full-hard and didn't get tempered for some reason?  Slightly out-of-round?

I "fire hose" sprayed helium on all of the metal joints on the YBM to see if I could get any response other than the known leaking feed-through on BSC8.  I found nothing -> We'll vent tomorrow and replace the leaking triax feed-through flange.  Some evidence suggests that GV1's gate annulus volume might leak into the YBM -> I pumped it with an aux. cart but didn't note the time line unfortunately.  

Also, I soft-closed GV6 and opened GV5 to allow me to leak test the joints between these two valves -> I found a small (1.3 x 10-8 torr*L/sec) leak on GV6's lead-screw nipple CF joint(s) but this size of leak is smaller than I was expecting -> we might "bag" these joints in the future or maybe check the calibration of PT-114 and PT-124 in an attempt to explain their apparent discrepancy in this pumping configuration.