Connected leak detector to TM1 and CS vacuum system. The vacuum readings on TM1 and CS:PNG4 3.6 xE-6 Torr, IG1 1.1xE-6torr, IG4(diagnostic box) 3.4xE-6 Torr. Leak detector base pressure:0.0xE-4 torr, base leak rate: 0.0xE-9 atm.cc/sec. Applied 80 psi helium to heat shield circuit for 4 mins . There is no response on leak detector. The heat shield circuit is leak tight.