TIAGO

HVAC 44 (II) EVACUATION AND RECHARGING 1. Add refrigerant oil as per the table given in “Re- plenishing Compressor Oil” procedure in the same section.  Evacuate the system according to the manufac- turer’s instructions NOTE If the vacuum reading is below 700mmHg after 15 minutes, suspect a leak in the system. Partially re- charge the system and check for leaks by using leak detector. Check suction lines first, then run the com- pressor for 5 minutes and then check the high pressure lines. ! CAUTION The system must be evacuated immediately before recharging commences. Delay between Evacuation and Recharging is not permitted . 2. Recharge the refrigerant as per instructions. Re- frigerant to be charged in the system is 500±20 gms. NOTE When charging refrigerant only without replacing any component, replenish the same amount of measured oil when recovering refrigerant (if not measured, re- plenish 30cc oil). 3. If the full charge has not been accepted by the system, start the engine and run it at 1500 rpm for a minimum of 2 minutes. Switch ON the air conditioning system, open the vehicle windows, set the temperature control to full cold and run the blower at maximum speed. 4. Consult Refrigerant Station Manual for correct procedure to complete the charge. 5. Carry out the air conditioning system perfor- mance test. B. FLUSHING OF AC SYSTEM Whenever there is an AC compressor failure the AC system should be flushed. This is done in order to remove the debris of the AC compressor that might have circulated through the system. The compressor used is piston type compressor. Flushing can be either done using an inverted de- canting R134a cylinder filled with refrigerant. In some recovering devices a flushing port is provided. NOTE  If a compressor is replaced without flushing, de- bris would circulate throughout the system. Hence all the components should be flushed  Flushing also removes excess oil from the sys- tem. If you suspect the system contains too much oil, flushing is a way to start fresh so you can es- tablish the correct quantity of refrigerant oil in the system. Following points should be noted while per- forming a flushing process 1. Flush individual components. 2. Self made flushing fitments will be required as AC system component fittings all differ in size, shape and thread size. 3. When replacing air conditioning parts with new ones, it is necessary to replenish oil by approxi- mately the same amount which was left in each part. 4. Reverse flush the components. 5. Do not flush through a compressor otherwise possible internal damage could occur. 6. Recycle the refrigerant recovered during flushing; the recovery device will remove contaminants through a filtration system.