A/C System Filtering

CAUTION: Follow all refrigerant system safety and service precautions.

NOTE: When A/C compressor replacement is caused by internal A/C compressor failure, the A/C system will become contaminated. To remove contamination from the A/C system, it is necessary to replace the suction accumulator/drier and the A/C evaporator core orifice. and to follow the filtering procedure. If the vehicle is equipped with auxiliary A/C, the auxiliary A/C evaporator filter must also be replaced.

Two A/C service kits have been released to provide the necessary equipment and information to perform the A/C system filtering procedure. Filter kits with the service part number suffix "A" are to be used on vehicles that have a nylon lined evaporator to compressor suction line between the suction accumulator/drier and the A/C compressor. Filter kits with the service part number suffix "B" are for vehicles with rubber lined hose.
1. To determine that the A/C compressor has failed and must be replaced, remove the A/C evaporator core orifice and liquid line, if necessary. Look for a dirty A/C evaporator core orifice and/or a liquid line containing black refrigerant oil and particles.
2. Remove the damaged A/C compressor and drain the oil into a calibrated container. Record the amount.
3. Drain the oil from the new A/C compressor into a calibrated container.

NOTE:
^ The proper amount of refrigerant oil must be added to the new A/C compressor before it can be installed.
^ It will be necessary to transfer the A/C clutch from the old A/C compressor to the new A/C compressor.

4. Add clean refrigerant oil to the new A/C compressor in the same amount that was removed from the old unit, plus an additional 30 ml (1 oz) of new refrigerant oil.
5. Install the new A/C compressor. Be sure the A/C compressor mounting bolts are tightened to the proper specification. Check the tension of the drive belt.







6. Determine the type of evaporator to compressor suction line with which you are working. To do this, cut the hose into two pieces (make the cut closer to the A/C compressor than the suction accumulator/drier) and measure the hose wall thickness. Rubber lined hose has a wall thickness of 6 mm (1/4 inch) and nylon lined hose has a wall thickness of 3 mm (1/8 inch).

Filter For Nylon Hose:

Filter For Rubber Hose:

7. Obtain the proper service kit for the vehicle being serviced. Filter kits with the service part number suffix "A" are to be used on vehicles with a nylon lined evaporator to compressor suction line. Filter kits with the service part number suffix "B" are for vehicles with a rubber lined evaporator to compressor suction line. The label on the filter shows with which hose it is to be used.
8. Remove a length of evaporator to compressor suction line to accommodate the evaporator to compressor suction line filter and install the filter using the hose clamps provided with the kit. Be sure the filter is correctly oriented for refrigerant system flow. Check the label on the filter. On the filter for nylon lined hose, install O-ring seals (two on each filter tube, being sure they are properly seated in the grooves on the tube). Tighten the hose clamps securely.
9. Install a new A/C evaporator core orifice.







10. Install a pancake filter in the condenser to evaporator tube between the A/C condenser core and the A/C evaporator core orifice. Be sure the filter inlet is toward the A/C condenser core. Connections can be made using Test Adapter Set D93L-19703-B or equivalent and flexible refrigerant hose of 17,000 kPa (2500 psi) burst rating. Individual fittings are also available.
11. Evacuate, charge, and leak test the system.
12. Check all refrigerant system hoses, lines and the positioning of the newly installed filters to be sure they do not interfere with other engine compartment components. If necessary, use tie straps to make adjustments.
13. Provide adequate air flow to the front of the vehicle (with a fan, if necessary) and turn the A/C switch on. Set the blower motor switch operation on high and the temperature control at full cool. Start the engine and let it idle briefly. Make sure the A/C system is operating properly.
14. Gradually bring the engine speed up to 1200 rpm by running it at lower rpms for short periods (first at 800 rpm, then at 1000 rpm). Set the engine at 1200 rpm and run it for an hour with the A/C system operating.
15. Stop the engine.
16. Allow the engine to cool sufficiently to remove the fittings, flexible hoses, and pancake filter from the condenser to evaporator tube. It will be necessary to discharge the system first.Refrigerant Recovery
17. Discard the pancake filter. It can be used ONE TIME ONLY.
18. Reconnect the condenser to evaporator tube into the system.
19. Evacuate, charge, and leak test the system. Make any necessary adjustments.
20. Check the operation of the system in all modes.