leak detector pumped down to 0.0xE-9 atm.cc/sec, and 0.0xE-4 torr. All high vacuum gauge readings at CS and TM4 are at low -6 range from 2.2xE-6torr to 4.2x E-6 torr. Applied 80 psi helium  to heat shield circuit for 5minutes and there is no any response on leak detector. The heat shield circuit is leak tight.