TB-9-2510-251-13 HMMWV Operator and Field Maintenance, Installation & Parts Add-On-Armor Air Conditioning Download
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4-23 TB 9-2510-251-13 4-14 Air Conditioning System Servicing (Cont’d) a. Discharge Air Conditioning System (Cont’d) 1) Tighten all connections and attach a vacuum pump to the center hose of the gauge set. 2) Start the vacuum pump and fully open both hand valves on the manifold. Run pump for five minutes. The system should reach a 30.0' Hg vacuum pressure within 90 seconds. 3) Close both hand valves and shut off vacuum pump. 4) Observe gauge readings for five minutes. If gauge needles move up, the system is not sealed. Check for loose connections or broken O-rings. Repeat Steps 1 through 4. 5) Run the vacuum pump for a minimum of one hour to remove all moisture from system. 6) Remove vacuum pump. b. Purge Air Conditioning System 1) Tighten all connections and attach a cylinder of dry nitrogen to the center hose of the gauge set. 2) Open nitrogen cylinder valve and allow to flow through system until all moisture is forced out. 3) Close nitrogen cylinder valve. 4) Tighten all connections and attach a vacuum pump to the center hose of the gauge set. 5) Start the vacuum pump and fully open both hand valves on the manifold. Run pump for five minutes. 6) Close both hand valves and shut off pump. 7) Observe gauge readings for five minutes. If gauge needles move up, the system is not sealed. Repeat Steps 4 through 7. 8) Run the vacuum pump at a 29.0” Hg vacuum for two hours.