Air Conditioning and Heating R-12 All Caterpillar Machines – Preparation of Air Conditioner Units for Seasonal Use

In order to improve the performance of the air conditioning units, regular maintenance must be performed before the air conditioning units are used. In order to decrease downtime, troubleshoot the air conditioning units before use. Failure to inspect the air conditioning units will cause the air conditioning units to fail prematurely. In order for the air conditioning unit to operate at optimum efficiency, all inspections must be performed.

  1. Clean the fresh air filters or install new fresh air filters. Clean the recirculating air filters or install new recirculating air filters.
  1. Inspect the condenser coils. Inspect the evaporator coils. If necessary, clean the coils. Do not steam clean the coils. In order to straighten the fins, use the 208-1350 Radiator Tool Gp (Fin Straightener).
  1. Inspect the drain lines for flow of condensate. Check for the proper location of the drain valve. If necessary, flush the lines with water and relocate the valve. The valve should be located between 0.0 mm (0.00 inch) and 76 mm (3 inch) from the end of the drain line.
  1. Inspect the wire connections for the compressor. If necessary, clean the wire connections for the compressor. To check clutch operation on systems with adjustable thermostats, turn the thermostat on and off. On some other systems, turn the A/C switch on and off. Systems that have the compressor protection system will need up to 30 seconds before the clutch engages.

    For systems that are not used for extended periods, run the compressor monthly for a minimum of 30 seconds. This will keep the shaft seal from drying out, leaking oil, and leaking refrigerant.

  1. Check the condition and tension of the compressor drive belt. For compressors that are driven by a V-belt, use 144-0235 Belt Tension Gauge .
  1. Check all hoses and connections for refrigerant leaks. Leaks can be identified by the following items: accumulation of oil, accumulation of dust and accumulation of dye. Check hoses for damaged areas. Replace hoses that are damaged. As required, add protection to the hoses or relocate the hoses.
  1. Do the performance check in this manual. The outside temperature needs to be at least 21 °C (70 °F).

    If the performance check shows a low charge and the system has been used for two or more years then perform the following steps:

    1. Inspect the system for leaks.
    1. Recover the system charge.
    1. Change the receiver-dryer, the dryer, the in-line dryer and the accumulator with desiccant.
    1. Evacuate the system for 30 minutes.
    1. Recharge the system according to the specifications.
    1. Inspect the system for leaks.
    1. Do the performance check again after the system has been charged.
  1. Remember that charging a system requires an exact charge by weight. The charge must be within 0.01 kg (0.022 lb) of the listed charge.
  1. Replace the dryer annually.
  1. Inspect the dust caps in order to ensure that the dust caps that are on the service ports are in place and that the dust caps are tight. Use 2L-1224 Air Conditioner Valve Cap for the high side or 8C-5248 Air Conditioner Valve Cap for the low side on R-12 systems.
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