TB-9-2510-251-13 HMMWV Operator and Field Maintenance, Installation & Parts Add-On-Armor Air Conditioning Download
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4-20 TB 9-2510-251-13 Section VI. UNIT MAINTENANCE PROCEDURES. WARNING • Do not attempt to perform any maintenance tasks on the kit while the vehicle is operating. Serious injury or death to personnel may result from failure to observe this warning. • All personnel should be familiar with and heed all safety warnings in the Warning Summary, page a, prior to performing any installation, removal, or maintenance for the Air Conditioner Kit. Failure to comply could result in injury or death to personnel and/or damage to equipment. • Prior to beginning any work on the Air Conditioner Kit: 1. Disconnect batteries 2. Apply parking brake 3. Chock wheels 4. Remove rings, bracelets, watches, necklaces, and any other jewelry. Failure to comply could result in injury or death to personnel and/or damage to equipment. CAUTION Refer to Repair Parts List (RPL), Appendix C, prior to beginning any installation steps for correct parts and hardware identification. Failure to comply could result in damage to equipment. 4-9 Hoses and Fittings When replacing hoses, be sure to use the same type and ID hose you removed. When hoses or fittings are shielded or clamped to prevent vibration damage, be sure these are in position or secured. On R-134a systems, make sure replacement hose has been designed for this refrigerant. Machine crimped fittings are preferred over those fittings which use hose clamps. Properly crimped ferrules make stronger connections than hose clamps and are recommended by the manufacturers of refrigerant hose. Use crimped fittings on hose brands such as Goodyear Galaxy. Steel fittings are preferred over aluminum in heavy duty applications. Use reusable fittings on the nylon-lined hose brands such as Aeroquip FC 202. 4-10 Expansion Valves When removing the expansion valve from the system, remove the insulation, clean the area, and disconnect the line from the receiver-drier. Detach the capillary (bulb) and external equalizer tube (if present) from their mounting locations. Remove the expansion valve from the evaporator inlet. Expansion valve service is limited to cleaning or replacing the filter screen. If this is not the problem, replace the valve. If there is any debris in a block-type valve, replace it. Secure the capillary and equalizer, if used, and replace any insulating material. 4-11 Expansion Tubes A clogged or defective expansion tube must be replaced. There are special tools available to remove and replace tubes at their location. If you don’t have one, you may be able to use a pair of needle-nose pliers. Put a little refrigerant oil in the evaporator inlet to lubricate the expansion tube for easier removal. Discard the old tube. Lubricate the new tube and O-ring and insert until it seats against the dimples in the evaporator inlet.