I leak checked the RbQ Vacuum Chamber because once again the pressure is stuck around 1.2E-6 Torr. My conclusion is that the leak followed the western 6"x12" plate when I rotated it. I thought that the leak was still at the western mating point between the rectangular prism frame and the cube frame, but I couldn't replicate it. There was generally weird behavior with the leak checker, the with the helium partial pressure going up and down for a 4 minute stretch, peaking at 1E-8 Torr L/s, way above the leaks from the chamber. 

I vented the chamber, took off the o-ring (it was quite easy to just pluck it away on the long end of the rectangle; I can't find the o-ring removal tool which might be needed for the square plates) from the problematic plate and added a fresh o-ring. I put the plate back in its most recent orientation and tightened the screws to 70 in-lbs. I started the scroll pump at 4:15 PM and the turbo pump at 4:22 PM with a pressure of 3.3E-2 Torr. 27 minutes after turning on the scroll, the pressure is 5.5E-6 Torr, which is similar to previous values.