2000 LEXUS GS400 engine

AC0WU±01
I02379
GS300:
PS Pump PS Pump Bracket
52 (530, 38)
Compressor Bracket
52 (530, 38)
58 (590, 43)
Drive Belt
52 (530, 38)
O±Ring
Discharge Hose
10 (100, 7)
Suction Hose
10 (100, 7)

O±Ring
26 (265, 19)
52 (530, 38)
52 (530, 38)
Engine Under Cover
GS400:
Drive Belt
10 (100, 7)
10 (100, 7)Discharge Hose
Suction Hose

O±Ring

O±Ring

O±Ring
10 (100, 7)
49 (500, 36)
29 (300, 22)
Stay
Engine Under Cover
Compressor
N´m (kgf´cm, ft´lbf): Specified torque

Non±reusable part
58 (590, 43)
Compressor
52 (530, 38)
AC±36
± AIR CONDITIONINGCOMPRESSOR AND MAGNETIC CLUTCH
2721 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
COMPONENTS

AC0WV±01
I02381
I02380
I02382
AC±38
± AIR CONDITIONINGCOMPRESSOR AND MAGNETIC CLUTCH
2723 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
1. RUN ENGINE AT IDLE SPEED WITH A/C ON FOR
APPROX. 10 MINUTES
2. STOP ENGINE
3. DISCONNECT NEGATIVE (±) TERMINAL CABLE
FROM BATTERY
4. DISCHARGE REFRIGERANT FROM REFRIGERATION
SYSTEM
5. REMOVE ENGINE UNDER COVER
6. REMOVE DRIVE BELT
(See page AC±15)
7. GS400:
DISCONNECT DISCHARGE HOSE
Remove the nut and disconnect the discharge hose.
NOTICE:
Cap the open fitting immediately to keep moisture or dirt
out of the system.
8. GS400:
REMOVE SUCTION HOSE
Remove the nut, bolt and suction hose.
NOTICE:
Cap the open fitting immediately to keep moisture or dirt
out of the system.
9. GS300:
DISCONNECT DISCHARGE AND SUCTION HOSES
Remove the 2 nut and disconnect the both hoses.
NOTICE:
Cap the open fitting immediately to keep moisture or dirt
out of the system.

± AIR CONDITIONINGCOMPRESSOR AND MAGNETIC CLUTCH
AC±45
2730 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. GS400:
INSTALL SUCTION HOSE
Install the suction hose with the bolt and nut.
Torque: 10 N´m (100 kgf´cm, 7 ft´lbf)
NOTICE:
Hose should be connected immediately after the caps have been removed.
HINT:
Lubricate 2 new O±rings with compressor oil and install them to the hose.
7. INSTALL DRIVE BELT
(See page AC±16)
8. INSPECT DRIVE BELT TENSION
(See page AC±14)
9. INSTALL ENGINE UNDER COVER
10. CONNECT NEGATIVE (±) TERMINAL CABLE TO BATTER
11. EVACUATE AIR FROM REFRIGERATION SYSTEM AND CHARGE SYSTEM WITH REFRIGERANT
Specified amount: 600 ± 50 g (21.16 ± 1.76 oz.)
12. INSPECT FOR LEAKAGE OF REFRIGERANT
Using a gas leak detector, check for leakage of refrigerant.
If there is leakage, check the tightening torque at the joints.
13. INSPECT A/C OPERATION

AC0X0±01
I02397
I02398
I02399
AC±48
± AIR CONDITIONINGCONDENSER
2733 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
1. DISCHARGE REFRIGERANT FROM REFRIGERATION
SYSTEM
HINT:
At the time of installation, please refer to the following item.
Evacuate air from refrigeration system.
Charge system with refrigerant and inspect for leakage of refrig-
erant.
Specified amount : 600 ± 50 g (21.16 ± 1.76 oz.)
2. REMOVE THESE PARTS:
(a) Air cleaner duct
(b) Air cleaner assembly
(c) 2 radiator upper supports
3. DISCONNECT DISCHARGE HOSE AND LIQUID TUBE
Remove the 2 bolts and disconnect the hose and tube.
Torque: 10 N´m (100 kgf´cm, 7 ft´lbf)
NOTICE:
Cap the open fittings immediately to keep moisture or dirt
out of the system.
HINT:
At the time of installation, please refer to the following item.
Lubricate 2 new O±rings with compressor oil and install them
to the hose and tube.
4. REMOVE CONDENSER
(a) Remove the 4 bolts and 2 brackets.
(b) Push the radiator toward engine.
(c) Push the condenser toward radiator and pull it upward.
HINT:
At the time of installation, please refer to the following item.
If condenser is replaced, add compressor oil to the condenser.
Add 40 cc (1.4 fl. oz)
Compressor oil: ND ± OIL 8 or equivalent

AC0X8±01
AC±58
± AIR CONDITIONINGEXPANSION VALVE
2743 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
EXPANSION VALVE
ON±VEHICLE INSPECTION
1. CHECK QUANTITY OF GAS DURING REFRIGERATION CYCLE
2. SET ON MANIFOLD GAUGE SET
(See page AC±17)
3. RUN ENGINE
Run the engine at 1,500 rpm for at least 5 minutes.
Then check that the high pressure reading is 1.37 ± 1.57 MPa (14 ± 16 kgf/cm
2, 199 ±228 psi).
4. CHECK EXPANSION VALVE
If the expansion valve is faulty, the low pressure reading will drop to 0 kPa (0 kgf/cm
2, 0 psi).

I03741
2 1
3
4
AC0XN±01
Z13470
Magnetic Clutch Control
Low Pressure Side
ON (Continuity)
181 kpa
(1.85 kgf´cm
2, 28 psi)
OFF (No Continuity)High Pressure Side
3,140 kpa
(32.0 kgf´cm2, 455 psi)
OFF (No Continuity)
Z13471
Cooling Fan Control
ON1,520 kpa
(15.5 kgf´cm
2, 220 psi)
(No Continuity) (Continuity)
OFF
1,230 kpa
(12.5 kgf´cm
2, 178 psi) AC±76
± AIR CONDITIONINGPRESSURE SWITCH
2761 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
PRESSURE SWITCH
ON±VEHICLE INSPECTION
1. SET ON MANIFOLD GAUGE SET
(See page AC±17)
2. DISCONNECT CONNECTOR FROM PRESSURE
SWITCH
3. RUN ENGINE AT APPROX. 1,500 RPM
4. Magnetic Clutch Control:
INSPECT PRESSURE SWITCH OPERATION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 4 and the negative (±) lead to terminal 1.
(b) Check continuity between terminals when refrigerant
pressure is changed, as shown in the illustration.
If operation is not as specified, replace the pressure switch.
5. Cooling Fan Control:
INSPECT PRESSURE SWITCH OPERATION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 2 and the negative (±) lead to terminal 3.
(b) Check continuity between terminals when refrigerant
pressure is changed, as shown in the illustration.
If operation is not as specified, replace the pressure switch.
6. STOP ENGINE AND SET OFF MANIFOLD GAUGE SET
7. CONNECT CONNECTOR TO PRESSURE SWITCH

AC0Y2±01
I03743
1 2 AC±80
± AIR CONDITIONINGCONDENSER FAN
2765 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
CONDENSER FAN
ON±VEHICLE INSPECTION
1. INSPECT CONDENSER FAN OPERATION
Inspect the fan operation, as shown in the chart below.
Test conditions:

Ignition switch ON

Blower speed control switch position ºHIº

Temperature control dial at ºMAX. COOLº

Install manifold gauge setº

A/C switch ON
ConditionFan operation (Fan speed)
Engine coolant temperature
91°C (196 °F) or belowRotate (Low speed)
Engine coolant temperature
100°C (212 °F) or aboveRotate (High speed)
Refrigerant pressure is less than
1,520 kPa (15.5 kgf´cm2, 220 psi)Rotate (Low speed)
Refrigerant pressure is 1,520 kPa
(15.5 kgf´cm2, 220 psi) or aboveRotate (High speed)
If operation is not as specified, proceed to the next inspection.
2. INSPECT CONDENSER FAN MOTOR OPERATION
(a) Disconnect the fan connector.
(b) Connect the positive (+) lead from the battery to terminal
2 and negative (±) lead to terminal 1 then check that motor
operations smoothly.

If operation is not as specified, replace the fan mo-
tor.

If operation is as specified, check the pressure
switch, cooling fan relays and engine coolant temp.
switch.

AC0Y4±01
AC±82
± AIR CONDITIONINGCONDENSER FAN
2767 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
1. DRAIN ENGINE COOLANT FROM RADIATOR
HINT:
It is not necessary to drain out all coolant.
2. REMOVE THESE PARTS:
(a) Air cleaner duct
(b) Air cleaner assembly
(c) Radiator reservoir tank cap
3. DISCONNECT THESE PARTS:
(a) Upper radiator hose
(b) Reservoir hose
4. REMOVE COOLING FAN
(a) Disconnect the connectors.
(b) Remove the 6 bolts cooling fan.