Scheme 88
Scheme 89
Scheme 90
- DO NOT HANDLE REFRIGERANT IN AN ENCLOSED AREA OR NEAR AN OPEN FLAME
- ALWAYS WEAR SAFETY GLASSES FOR EYE PROTECTION
- AVOID YOUR EYES AND SKIN TO CONTACT WITH LIQUID REFRIGERANT If you get the liquid refrigerant in your eyes or on your skin: Wash out the area with lots of cold water. CAUTION: Do not rub your eyes or skin. Apply clean petroleum jelly to the skin. Go immediately to a physician or hospital for professional treatment.
- NEVER HEAT CONTAINER OR EXPOSE IT TO NAKED FLAME
- BE CAREFUL NOT TO DROP CONTAINER AND NOT TO APPLY PHYSICAL SHOCKS TO IT Do not drop container nor apply physical shocks to it.
- DO NOT OPERATE COMPRESSOR WITHOUT ENOUGH REFRIGERANT IN REFRIGERANT SYSTEM If there is not enough refrigerant in the refrigerant system, oil lubrication will be insufficient and compressor burnout may occur. To avoid this, always keep enough refrigerant in the refrigerant system.
- DO NOT OPEN HIGH PRESSURE MANIFOLD VALVE WHILE COMPRESSOR IS OPERATING If the high pressure valves opened, refrigerant flows in the reverse direction and could cause the charging cylinder to rupture, so open and close the only low pressure valve.
- DO NOT OVERCHARGE REFRIGERANT SYSTEM WITH REFRIGERANT If refrigerant is overcharged, it causes problems such as insufficient cooling, poor fuel economy, engine overheating etc.
- SUPPLEMENTAL RESTRAINT SYSTEM (SRS) The LEXUS LX470 is equipped with SRS (Supplemental Restraint System) such as the driver airbag and the front passenger airbag. Failure to carry out service operation in the correct sequence could cause the SRS to unexpectedly deploy during servicing, possibly leading to a serious accident. Before servicing (including removal or installation of parts, inspection or replacement), be sure to read the precautionary notices in the «AIR BAG SAFETY PRECAUTIONS»
Scheme 91
Scheme 91: ON-VEHICLE INSPECTION
Scheme 92
Scheme 93
Scheme 94
Scheme 95
Scheme 96
Scheme 97
Scheme 98
Scheme 99
Scheme 100
- INSPECT REFRIGERANT VOLUME Observe the sight glass on the liquid tube. Test conditions: Engine speed at 1,500 RPM Blower speed control switch at "HI" position A/C switch ON Temperature control dial at "COOL" position Doors fully opened SYMPTOM REFRIGERANT AMOUNT Item Symptom Amount of refrigerant Remedy 1 Bubbles appear in sight glass Insufficient (1) Check for gas leakage with gas leak detector and repair, if necessary Add refrigerant until bubbles disappear 2 No bubbles appear in sight glass None, sufficient or too much Refer to item 3 and 4 3 No temperature difference between compressor inlet and outlet Empty or nearly empty Check for gas leakage with gas leak detector and repair, if necessary Add refrigerant until bubbles disappear 4 Temperature between compressor inlet and outlet is noticeably different Correct or too much Refer to items 5 and 6 5 Immediately after air conditioning system is turned off, refrigerant in sight glass stays clear Too much Discharge refrigerant Evacuate air and charge proper amount of purified refrigerant 6 When air conditioning system is turned off, refrigerant foams and then stays clear Correct - (1) Bubbles in the sight glass with ambient temperatures higher than usual can be considered normal if cooling is sufficient.
- INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET Check the trouble area using a set of manifold gauge set. Read the manifold gauge pressure when following conditions are detected. Test conditions: Temperature at the air inlet with the switch set at RECIRC is 30 - 35°C (86 - 95°F) Engine speed at 2,000 RPM Blower speed control switch at "HI" position Temperature control dial on "COOL" position HINT: It should be noted that the gauge indications may vary depending on ambient temperature conditions. Normally functioning refrigeration system. Gauge reading: Low pressure side: 0.15 - 0.25 MPa (1.5 - 2.5 kgf/cm 2 ) High pressure side: 1.37 - 1.57 MPa (14-15 kgf/cm 2 ) Moisture present in refrigeration system. SYMPTOM REFRIGERANT AMOUNT Symptom seen in refrigeration system Probable cause Diagnosis Remedy During operation, pressure on low pressure side sometimes become a vacuum and sometime normal Moisture entered in refrigeration system freezes at expansion valve orifice and temporarily stops cycle, but normal state is restored after a time when the ice melts Drier in over-saturated state Moisture in refrigeration system freezes at expansion valve orifice and blocks circulation of refrigerant Replace condenser Remove moisture in cycle through repeatedly evacuating air Charge proper amount of new refrigerant Insufficient cooling SYMPTOM REFRIGERANT AMOUNT Symptom seen in refrigeration system Probable cause Diagnosis Remedy Pressure low on both low and high pressure sides Bubbles seen in sight glass continuously Insufficient cooling performance Gas leakage at some place in refrigeration system Insufficient refrigerant in system Refrigerant leaking Check for gas leakage with gas leak detector and repair if necessary Charge proper amount of refrigerant If indicated pressure value is near 0 when connected to gauge, create the vacuum after inspecting and repairing the location of the leak Poor circulation of refrigerant SYMPTOM REFRIGERANT AMOUNT Symptom seen in refrigeration system Probable cause Diagnosis Remedy Pressure low in both low and high pressure sides Frost on tube from condenser to unit Refrigerant flow obstructed by dirt in condenser condenser clogged Replace condenser Refrigerant does not circulate SYMPTOM REFRIGERANT AMOUNT Symptom seen in refrigeration system Probable cause Diagnosis Remedy Vacuum indicated on low pressure side, very low pressure indicated on high pressure side Frost or dew seen on piping before and after condenser/drier or expansion valve Refrigerant flow obstructed by moisture or dirt in refrigeration system Refrigerant flow obstructed by gas leakage from expansion valve Refrigerant does not circulate Check expansion valve Clean out dirt in expansion valve by blowing with air Replace condenser Evacuate air and charge new refrigerant to proper amount For gas leakage from expansion valve, replace expansion valve Refrigerant overcharged or insufficient cooling of condenser SYMPTOM REFRIGERANT AMOUNT Symptom seen in refrigeration system Probable cause Diagnosis Remedy Pressure too high on both low and high pressure sides No air bubbles seen through the sight glass even when the engine rpm is lowered Unable to develop sufficient performance due to excessive refrigeration system Insufficient cooling of condenser Excessive refrigerant in cycle --> refrigerant over charged Condenser cooling --> condenser fins clogged of cooling fan faulty Clean condenser Check cooling fan with fluid coupling operation If (1) and (2) are in normal state, check amount of refrigerant, and charge proper amount of refrigerant Air present in refrigeration system SYMPTOM REFRIGERANT AMOUNT Symptom seen in refrigeration system Probable cause Diagnosis Remedy Pressure too high on both low and high pressure sides The low pressure piping hot to touch Bubbles seen in sight glass Air entered in refrigeration system Air present in refrigeration system Insufficient vacuum purging Check compressor oil to see if it is dirty or insufficient Evacuate air and charge new refrigerant Expansion valve improperly SYMPTOM REFRIGERANT AMOUNT Symptom seen in refrigeration system Probable cause Diagnosis Remedy Pressure too high on both low and high pressure sides Frost or large amount of dew on piping on low pressure side Trouble in expansion valve Excessive refrigerant in low pressure piping Expansion valve opened too wide Check expansion valve, and replace if defective Defective compression compressor SYMPTOM REFRIGERANT AMOUNT Symptom seen in refrigeration system Probable cause Diagnosis Remedy Pressure too high on low and high pressure sides Pressure too low on high pressure side Internal leak in compressor Compression defective Valve leaking or broken sliding parts Repair or replace compressor
- INSPECT IDLE-UP SPEED Warm up engine Inspect idle-up speed when following conditions are established. Test conditions: Blower speed control switch at "HI" position Temperature control dial at "COOL" position A/C switch ON Put gear shift in neutral MAGNETIC CLUTCH CONDITION Magnetic clutch condition Idle-up speed Magnetic clutch not engaged 750 +/- 50 rpm Magnetic clutch engaged 780 +/- 50 rpm If idle speed is not as specified, check the idle control system.
- INSPECT FOR LEAKAGE OF REFRIGERANT Perform in these conditions. Stop engine Secure good ventilation (The gas leak detector may not react to volatile gases which are not refrigerant, such as evaporated gasoline and exhaust gas) Repeat the test 2 or 3 times Make sure that there is some refrigerant remaining in the refrigeration system. When compressor is OFF: approx. 392 - 588 kPa (4-6 kgf-cm 2 , 57 - 85 psi) Bring the gas leak detector close to the drain hose before performing the test. HINT: After the blower motor stops, leave the cooling for more than 15 minutes. Expose the gas leak detector sensor under the drain hose. When bring the gas leak detector close to the drain hose, make sure that the gas leak detector does not react to the volatile gases. If gas leaks are detected, lift up the vehicle. If gas leaks are not detected on the drain hose, remove the blower resistor from the cooling unit. Then insert the gas leak detector sensor into the unit to perform the test. Disconnect the connector and leave the pressure switch for approx. 20 minutes. Then bring the gas leak detector close to the pressure switch to perform the test. Bring the gas leak detector close to the refrigerant lines.
Scheme 101
Scheme 102
Scheme 103
- CONNECT QUICK DISCONNECT ADAPTER TO CHARGING HOSES
- REMOVE CAPS FROM SERVICE VALVES ON REFRIGERANT LINES
- SET ON MANIFOLD GAUGE SET Close both the hand valves of the manifold gauge set. Connect the quick disconnect adapters to the service valves.
- EVACUATE AIR FROM REFRIGERATION SYSTEM Connect the vacuum pump adapter to the vacuum pump. Connect the center hose of the manifold gauge set to the vacuum pump adapter. Open both the high and low hand valves and run the vacuum pump. After 10 minutes or later, check that the low pressure gauge indicates 750 mmHg (30 in. Hg) minimum. HINT: If the reading is higher than 750 mmHg (30 in. Hg), close both the hand valves of the manifold gauge set and stop the vacuum pump. Check the system for leaks and repair if necessary. Close both the high and low hand valves and stop the vacuum pump. Leave the system in this condition for at least 5 minutes and check that there is no gauge indicator.
Scheme 104
Scheme 105
Scheme 106
Scheme 107
- INSTALL CHARGING CYLINDER HINT: When handling the charging cylinder, always follow the directions given in the instruction manual. Charge the proper amount of refrigerant into the charging cylinder. Connect the center hose to the charging cylinder. CAUTION: Do not open both high and low hand valves of manifold gauge set. Open the valve of the charging cylinder. Press the valve core on the side of manifold gauge and expel the air inside the center hose.
- INSPECT REFRIGERATION SYSTEM FOR LEAKS Open the high pressure hand valve and charge the refrigerant. When the low pressure gauge indicates 98 kPa (1 kgf/cm 2 , 14 psi), close the high pressure hand valve. Using a gas leak detector, check the system for any leakage. If leaks are found, repair the faulty component or connection. CAUTION: Use the refrigerant recovery/recycling machine to recover the refrigerant whenever replacing parts.
- CHARGE REFRIGERANT INTO REFRIGERATION SYSTEM If there is no leak after refrigerant leak check, charge the proper amount of refrigerant into the refrigeration system. CAUTION: Do not run the engine when charging the system through the high pressure side. Do not open the low pressure hand valve when the system is being charged with liquid refrigerant. Open the high pressure hand valve fully. Charge specified amount of refrigerant, then close the high pressure hand valve. HINT: No bubbles in the sight glass indicates that the system is fully charged. Partially charge the refrigeration system with refrigerant. Set vehicle in these conditions: Running engine at 1,500 RPM Blower speed control set at "HI" Temperature control set at "MAX. COOL" Air inlet control set at "RECIRC" Fully open doors (Sliding roof: closed) Open the low pressure hand valve. CAUTION: Do not open the high pressure hand valve. Charge refrigerant until bubbles disappear and check the pressure on the gauge through the sight glass.
Scheme 108
Scheme 109
Scheme 110
Scheme 110: ON-VEHICLE INSPECTION
Scheme 111
- INSPECT DRIVE BELT'S INSTALLATION CONDITION Check that drive belt fits properly in the ribbed grooves.
- INSPECT DRIVE BELT TENSION Check that the tension is within A range on the auto tensioner scale. If the tension is not within the A range on the scale, replace the belt with a new one. HINT: When replacing the drive belt with a new one, the belts tension should be within the B range on the belt tensioner scale.
