HVAC System - Air Conditioning: Other Mercury Monterey VIII

A/C Compressor Pressure Relief Valve

An A/C compressor pressure relief valve is incorporated in the compressor manifold and tube assembly to

1. relieve unusually high refrigerant system discharge pressure buildups.
2. prevent damage to the A/C compressor and other system components.
3. avoid total refrigerant loss by closing after the excessive pressure has been relieved.

Condenser Core

Note. Installation of a new suction accumulator is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

The condenser core has the following characteristics

1. It is an aluminum fin and tube design heat exchanger located in front of the vehicle radiator.
2. It cools compressed refrigerant gas by allowing air to pass over fins and tubes to extract heat and by condensing gas to liquid refrigerant as it is cooled.

Refrigerant Lines

Note. Installation of a new suction accumulator is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

The compressor manifold and tube assembly is attached to the A/C compressor, is sealed with O-ring seals and has the following features

1. The upstream side contains low pressure refrigerant gas.
2. The downstream side contains high pressure refrigerant gas and a fitting used to mount a serviceable high-pressure A/C charge port valve.
3. The downstream side also contains a fitting used to mount the A/C pressure transducer. A long-travel Schrader-type valve stem core is installed in the fitting so that the A/C pressure transducer can be removed without discharging the A/C system.

Evaporator Core

Note. Installation of a new suction accumulator is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

The evaporator core is the plate/fin type.

1. A mixture of refrigerant and oil enters the evaporator core through the evaporator core inlet tube, continues over to the remaining 5 plate/fin sections, and then moves out of the evaporator core through the evaporator core outlet tube.
2. All airflow from the blower motor passes through the evaporator core before being mixed and distributed.

Evaporator Core Orifice Tube

Note. A new evaporator core orifice tube should be installed whenever a new A/C compressor is installed.

The A/C evaporator core orifice has the following characteristics

1. It is color-coded orange.
2. It is located in the condenser to evaporator line.
3. It has filter screens located on the inlet and outlet ends of the tube body.
4. The inlet filter screen acts as a strainer for the liquid refrigerant flowing through the evaporator core orifice tube.
5. O-ring seals on the evaporator core orifice tube prevent the high-pressure liquid refrigerant from bypassing the evaporator core orifice tube.
6. It can be accessed through a fitting in the condenser to evaporator line.
7. Adjustment or service cannot be carried out to the evaporator core orifice tube. A new evaporator core orifice must be installed.

Suction Accumulator

Note. Installation of a new suction accumulator is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

The suction accumulator is mounted near the RH shock tower. The evaporator outlet line attaches directly to the inlet of the suction accumulator and the compressor manifold and tube assembly attaches to the suction accumulator outlet.

After entering the inlet of the suction accumulator, the heavier oil-laden refrigerant contacts an internally mounted dome (which serves as an umbrella) and drips down onto the bottom of the canister.

1. A small diameter oil bleed hole, in the bottom of the vapor return tube, allows the accumulated heavier liquid refrigerant and oil mixture to reenter the compressor suction line at a controlled rate.
2. As the heavier mixture passes through the small diameter liquid bleed hole, it has a second chance to vaporize and recirculate through the A/C compressor without causing compressor damage due to slugging.
3. A fine mesh screened filter fits tightly around the bottom of the vapor return inlet to filter out refrigerant system contaminant particles.
4. A desiccant bag is mounted inside the canister to absorb any moisture which may be in the refrigerant system.

Air Conditioning (A/C) Cycling Switch

The A/C cycling switch is mounted on a Schrader valve-type fitting on the suction accumulator.

1. The A/C cycling switch is used by the PCM to indicate if A/C refrigerant low side pressures are within operating specifications for A/C compressor operation. A 12-volt signal is supplied by the smart junction box (SJB) when the ignition is in the run position to the cycling switch.
2. A valve depressor, located inside the threaded end of the A/C cycling switch, presses in on the Schrader valve stem.
3. This allows the suction pressure inside the suction accumulator to control the operation of the A/C cycling switch.
4. The electrical switch contacts open when the suction pressure drops. The contacts close when the suction pressure rises.
5. When the A/C cycling switch contacts close, the 12-volt signal is sent to the PCM indicating A/C refrigerant low side pressures are within operating specifications for A/C compressor operation.
6. When the A/C cycling switch contacts open, the 12-volt signal to the PCM is interrupted, indicating A/C refrigerant pressures are below operating specifications for A/C compressor operation.
7. The A/C cycling switch will control the evaporator core pressure at a point where the plate/fin surface temperature will be maintained slightly above freezing.
8. This prevents icing of the evaporator core and blockage of airflow.
9. It is not necessary to recover the refrigerant system to remove the A/C cycling switch.

A/C Pressure Transducer

The pressure transducer is used to interrupt A/C compressor operation in the event of high system discharge pressures.

1. The A/C pressure transducer is used by the PCM to monitor A/C refrigerant high side pressures. A 5-volt reference voltage, ground and feedback circuit is provided by the PCM to the A/C pressure transducer. Feedback voltage will vary in correlation to A/C refrigerant high side pressures.
2. The pressure transducer is mounted on a Schrader-type valve fitting on the high pressure side of the compressor manifold and tube assembly.
3. A valve depressor, located inside the threaded end of the pressure transducer, presses on the Schrader valve stem.
4. This allows the pressure transducer to monitor the A/C compressor discharge pressure.
5. If A/C refrigerant high side pressures reach a predetermined pressure, the PCM will enable engine cooling fan high speed operation. If pressures continue to rise, the PCM will disable A/C compressor operation via the A/C relay. Once A/C refrigerant high side pressures fall below the predetermined level, the PCM will enable the A/C compressor (if all other A/C compressor inputs are within range).
6. It is not necessary to recover the refrigerant system to remove the pressure transducer.

Service Gauge Port Valves

The high-pressure service gauge port valve is located on the compressor manifold and tube assembly near the condenser fitting.

The low-pressure service gauge port valve is located on the evaporator-to-suction accumulator line near the evaporator fitting.

Scheme 12

The fitting is an integral part of the refrigeration line or component.

1. Special couplings are required for both the high-side and low-side service gauge ports.
2. A very small amount of leakage will always be detectable around the Schrader-type valve with the service gauge port valve cap removed, and is considered normal. A new Schrader-type valve core can be installed if the seal leaks excessively.
3. The service gauge port valve caps are used as primary seals in the refrigerant system to prevent leakage through the Schrader-type valves from reaching the atmosphere. Always install and tighten the A/C service gauge port valve caps to the correct torque after they are removed.

Refrigerant System Dye

Fluorescent refrigerant system dye is added to the refrigerant system at the factory to assist in refrigerant system leak diagnosis using a Rotunda-approved ultraviolet blacklight. It is not necessary to add additional dye to the refrigerant system before diagnosing leaks, even if a significant amount of refrigerant has been removed from the system. New suction accumulators are shipped with a fluorescent dye "wafer" included in the desiccant bag which will dissolve after approximately 30 minutes of continued A/C operation. It is not necessary to add dye after flushing or filtering the refrigerant system because a new suction accumulator is installed as part of the flushing or filtering procedure. Additional refrigerant system dye should only be added if more than 50% of the refrigerant system lubricant capacity has been lost due to a fitting separation, hose rupture or other damage. For additional information, refer to CLIMATE CONTROL SYSTEM-GENERAL INFORMATION .

Refer to CLIMATE CONTROL SYSTEM-GENERAL INFORMATION .

Material

MATERIAL SPECIFICATIONS

Scheme 13

Note. Installation of a new suction accumulator is not required when repairing the air conditioning system, except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

Scheme 14

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1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to «JACKING & LIFTING»(ref-234483) .
2. Recover the refrigerant. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
3. Remove the generator. For additional information, refer to «GENERATOR AND REGULATOR»(ref-234495) .
4. Disconnect the clutch field coil electrical connector.
5. Completely loosen the A/C compressor mounting bolt. To install, tighten to 25 Nm (18 lb-ft).
6. Remove the 3 bolts from the A/C mounting bracket. To install, tighten to 25 Nm (18 lb-ft).
7. Remove the 2 bolts from the generator mounting bracket. To install, tighten to 48 Nm (35 lb-ft).
8. Completely loosen the generator mounting bracket bolt. To install, tighten to 48 Nm (35 lb-ft).
9. Lift the generator mounting bracket until the remaining bolt clears the frame rail and remove the bolt. Remove the generator mounting bracket.
10. Remove the RH cooling fan and shroud assembly bolt.
11. Completely loosen the 2 lower compressor bolts. To install, tighten to 25 Nm (18 lb-ft).
12. Remove the A/C compressor manifold bolt. To install, tighten to 20 Nm (15 lb-ft).
13. Completely loosen the 2 upper compressor bolts. To install, tighten to 25 Nm (18 lb-ft).
14. Remove the A/C compressor. Discard the O-ring seals.
15. Remove the compressor bracket.
16. To install, reverse the removal procedure. Install new O-ring seals lubricated in clean mineral oil. Lubricate the refrigerant system with the correct amount of clean PAG oil. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
17. If filtering of the A/C system is not to be carried out, evacuate, leak test and charge the refrigerant system. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .

MATERIAL SPECIFICATIONS

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1. Remove the A/C compressor (19703). For additional information, refer to «AIR CONDITIONING (A/C) COMPRESSOR»(ref-234497-S01568185462006061000000) .
2. Remove the A/C clutch disc and hub retaining bolt. Hold the A/C clutch disc and hub with the special tool. Remove the bolt.
3. Remove the A/C clutch disc and hub.
4. Remove the shaft seal felt from the nose of the A/C compressor with the special tool.
5. Clean the compressor nose area.
6. Insert the tip of the special tool into one of the snap ring eyes.
7. Rotate the special tool to position the tool tip and the snap ring eye closest to the A/C compressor shaft.
8. Pull the special tool up quickly while keeping the tool shaft against the side of the nose opening and remove the snap ring.
9. Engage the special tool into the inside diameter of the shaft seal.
10. Turn the tool handle clockwise to expand the tool tip inside of the shaft seal.
11. Pull the seal from the A/C compressor.

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1. Clean the A/C compressor nose area.
2. Place the shaft seal on the special tool. Lubricate the shaft seal and the special tool with mineral oil or equivalent.
3. Position the shaft seal and the special tool over the A/C compressor shaft.
4. Push the shaft seal onto the A/C compressor shaft with the special tool until seated.
5. Install the shaft seal snap ring.
6. Carry out the A/C Compressor-External Leak Test. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
7. Install the shaft seal felt.
8. Install the A/C clutch disc and hub.
9. Install the bolt. Hold the A/C clutch disc and hub with the special tool. Tighten to 13 Nm (10 lb-ft).
10. Measure and adjust the clutch air gap by removing or adding A/C clutch hub spacers.
11. Install the A/C compressor. For additional information, refer to «AIR CONDITIONING (A/C) COMPRESSOR»(ref-234497-S01568185462006061000000) .

MATERIAL SPECIFICATIONS

Scheme 35

Note. Installation of a new suction accumulator is not required when repairing the air conditioning system, except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

Scheme 36

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Scheme 40

1. Recover the refrigerant. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
2. Remove the wiper arm and pivot shaft. For additional information, refer to «WIPERS AND WASHERS»(ref-234530) .
3. Remove the nuts and the fresh air inlet duct.
4. Disconnect the condenser-to-evaporator line fitting at the evaporator core. Discard the O-ring seals.
5. Disconnect the evaporator core orifice fitting and remove the evaporator end of the condenser-to-evaporator line. Discard the O-ring seal.
6. Inspect the evaporator core orifice for damage before attempting to remove it from the line.
7. If the evaporator core orifice is intact, engage the special tool. Hold the T-handle stationary while rotating the tool body to remove the evaporator core orifice.
8. If the evaporator core orifice is broken, screw the end of the special tool into the broken orifice. Hold the T-handle stationary while rotating the tool body to remove the evaporator core orifice.

Scheme 41

1. Lubricate the evaporator core orifice O-rings in clean PAG oil and install the evaporator core orifice using the special tool.
2. Install the evaporator end of the condenser-to-evaporator line and connect the evaporator core orifice fitting. Install new O-ring seals.
3. Connect the condenser-to-evaporator line fitting at the evaporator core. Install new O-ring seals.
4. Install the fresh air inlet duct.
5. Install the wiper arm and pivot shaft. For additional information, refer to «WIPERS AND WASHERS»(ref-234530) .
6. Lubricate the refrigerant system with the correct amount of clean PAG oil. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
7. Evacuate, leak test and charge the refrigerant system. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .

MATERIAL SPECIFICATIONS

Scheme 42

Note. Installation of a new suction accumulator is not required when repairing the air conditioning system, except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

1. Recover the refrigerant. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
2. Remove the 2 A/C fitting nuts. Discard the O-ring seals. To install, tighten to 8 Nm (71 lb-in).
3. Disconnect the A/C cycling switch electrical connector.
4. Remove the 3 suction accumulator bolts.
5. Remove the suction accumulator.
6. To install, reverse the removal procedure. Install new O-ring seals lubricated in clean mineral oil. Lubricate the refrigerant system with the correct amount of clean PAG oil. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
7. Evacuate, leak test and charge the refrigerant system. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .

MATERIAL SPECIFICATIONS

Scheme 43

Scheme 44

Note. Installation of a new suction accumulator is not required when repairing the air conditioning system, except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

Scheme 45

1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to «JACKING & LIFTING»(ref-234483) .
2. Recover the refrigerant. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
3. Remove the condenser outlet fitting nut. Discard the O-ring seal. To install, tighten to 8 Nm (71 lb-in).
4. Remove the 5 bumper cover screws.
5. Remove the condenser inlet fitting nut. Discard the O-ring seal. To install, tighten to 8 Nm (71 lb-in).
6. Remove the compressor manifold and tube bracket bolt.
7. Disconnect the cooler line clip.
8. Detach the line routing clips from the lower radiator support.
9. Correctly support the lower radiator support and remove the 4 lower radiator support bolts.
10. Correctly support the cooling module and remove the lower radiator support.
11. Remove the 2 condenser bracket bolts.
12. Remove the condenser core.
13. Remove the 2 condenser brackets.
14. To install, reverse the removal procedure. Install new O-ring seals lubricated in clean mineral oil. Lubricate the refrigerant system with the correct amount of clean PAG oil. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
15. Evacuate, leak test and charge the refrigerant system. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .

MATERIAL SPECIFICATIONS

Scheme 46

Note. Installation of a new suction accumulator is not required when repairing the air conditioning system, except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to «JACKING & LIFTING»(ref-234483) .
2. Recover the refrigerant. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
3. Remove the suction accumulator outlet fitting nut. Discard the O-ring seal. To install, tighten to 8 Nm (71 lb-in).
4. Remove the auxiliary line fitting nut. Discard the O-ring seal. To install, tighten to 8 Nm (71 lb-in).
5. Remove the compressor manifold and tube bracket bolt.
6. Disconnect the high pressure switch electrical connector.
7. Remove the compressor manifold bolt. Discard the O-ring seals. To install, tighten to 21 Nm (15 lb-ft).
8. Remove the condenser inlet fitting nut. Discard the O-ring seal. To install, tighten to 8 Nm (71 lb-in).
9. Remove the compressor manifold and tube assembly.
10. To install, reverse the removal procedure. Install new O-ring seals lubricated in clean mineral oil. Lubricate the refrigerant system with the correct amount of clean PAG oil. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
11. Evacuate, leak test and charge the refrigerant system. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .

MATERIAL SPECIFICATIONS

Scheme 47

Note. Installation of a new suction accumulator is not required when repairing the air conditioning system, except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

1. With the vehicle in NEUTRAL, position it on a hoist. For additional information refer to «JACKING & LIFTING»(ref-234483) .
2. Recover the refrigerant. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
3. Remove the wiper motor and pivot assembly. For additional information, refer to «WIPERS AND WASHERS»(ref-234530) .
4. Remove the 2 fresh air inlet duct nuts.
5. Remove the fresh air inlet duct.
6. Disconnect the evaporator inlet fitting. Discard the O-ring seals.
7. Disconnect the evaporator core orifice access fitting. Discard the O-ring seal.
8. Remove the evaporator outlet line bracket bolt. To install, tighten to 8 Nm (71 lb-in).
9. Remove the 2 condenser-to-evaporator line bracket bolts. To install, tighten to 8 Nm (71 lb-in).
10. Remove the condenser outlet fitting nut. Discard the O-ring seal. To install, tighten to 8 Nm (71 lb-in).
11. Remove the auxiliary line fitting nut. Discard the O-ring seal. To install, tighten to 8 Nm (71 lb-in).
12. Remove the condenser-to-evaporator line.
13. To install, reverse the removal procedure. Install new O-ring seals lubricated in clean mineral oil. Lubricate the refrigerant system with the correct amount of clean PAG oil. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .
14. Evacuate, leak test and charge the refrigerant system. For additional information, refer to «CLIMATE CONTROL SYSTEM-GENERAL INFORMATION»(ref-234501) .

Scheme 48

1. Remove the heater core and evaporator core housing. For additional information, refer to «HEATING & VENTILATION»(ref-234545) .
2. Remove 11 screws and the evaporator core cover.
3. Remove the evaporator core.
4. To install, reverse the removal procedure.