This morning, the vacuum responded to shutting of the water of the heat shield circuit (leak rate without pumping leveling out). The vacuum chamber was vented and the heat shield with flexible lines was replaced with another heat shield with fixed lines. The chamber was again pumped down and water opened at ~150 mTorr to test the leak up rate without pumping. No leaks apparent, so continued pumping down with turbo pump. At a vacuum of about 1E-6 Torr the water was again supplied to the heat shield circuit and an increase in vacuum could be observed. Stopped the turbo pump and prepared to vent. Two new heat shield lines were brazed in the machine shop and fitted by Maico after lunch. During this time one of the old lines (from heat shield to feedthrough in box) was leak tested and a leak found at a location just above the VCR. The line had been twisted and due to the twist developed a leak. With the two lines replaced, the vacuum was pumped down again and water could be supplied without any increase in vacuum pressure at 1E-6 Torr. To facilitate the new copper tubing, the restraining bracket for the heat shield VCRs was not mounted. It will have to be fitted later. Until then, please contact Anders for help in removing the heat shield to prevent any damage to the new lines.