2000 LEXUS GS400 water pump

CO0A3±01
B01940
± COOLING (2JZ±GE)THERMOSTAT
CO±11
1549 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
HINT:
Removal of the thermostat would have an adverse effect, caus-
ing a lowering of cooling efficiency. Do not remove the thermo-
stat, even if the engine tends to overheat.
1. DRAIN ENGINE COOLANT
2. DISCONNECT WATER INLET FROM WATER PUMP,
AND REMOVE THERMOSTAT
(a) Remove the 2 nuts holding the water inlet to the water
pump, and disconnect the water inlet from the water
pump.
(b) Remove the thermostat.
(c) Remove the gasket from the thermostat.

CO0A7±01
CO1242
Radiator Cap Tester
Radiator Cap
30° or More
B01882
Radiator Cap Tester
± COOLING (2JZ±GE)RADIATOR
CO±15
1553 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
ON±VEHICLE INSPECTION
1. REMOVE RADIATOR CAP
Remove the radiator cap from the radiator.
CAUTION:
To avoid the danger of being burned, do not remove the ra-
diator cap while the engine and radiator are still hot, as fluid
and steam can be blown out under pressure.
2. INSPECT RADIATOR CAP
NOTICE:

If the radiator cap has contaminations, always rinse
it with water.

Before using a radiator cap tester, wet the relief valve
and pressure valve with engine coolant or water.

When performing steps (a) and (b) below, keep the
tester at an angle of over 30° above the horizontal.
(a) Using a radiator cap tester, slowly pump the tester and
check that air is coming from the vacuum valve.
Pump speed: 1 push/(3 seconds or more)
NOTICE:
Push the pump at a constant speed.
If air is not coming from the vacuum valve, replace the radiator
cap.
(b) Pump the radiator cap tester, and measure the relief valve
opening pressure.
Pump speed: 1 push within 1 second
NOTICE:
This pump speed is for the first pump only (in order to close
the vacuum valve). After this, the pump speed can be re-
duced.
Standard opening pressure:
93 ± 123 kPa (0.95 ± 1.25 kgf/cm
2, 13.5 ± 17.8 psi)
Minimum opening pressure:
78 kPa (0.8 kgf/cm
2, 11.4 psi)
HINT:
Use the tester's maximum reading as the opening pressure.
If the opening pressure is less than minimum, replace the radia-
tor cap.
3. INSPECT COOLING SYSTEM FOR LEAKS
(a) Fill the radiator with coolant and attach a radiator cap tes-
ter.
(b) Warm up the engine.
(c) Pump it to 118 kPa (1.2 kgf/cm
2, 17.1 psi), and check that
the pressure does not drop.
If the pressure drops, check the hoses, radiator or water pump
for leaks. If no external leaks are found, check the heater core,
cylinder block and head.
4. REINSTALL RADIATOR CAP

CO09Y±01
A02724
Air Cleaner Inlet
Upper Radiator Support
MAF Meter Connector Air Cleaner and MAF
Meter AssemblyLower Radiator Hose
Radiator
Assembly
ECM Outlet Duct
ECT
Switch
Engine Wire Clamp EVAP Hose
Lower Radiator Support
Intake Air Resonator
PS Pump
Front Bracket
Water Pump Pulley
Drive Belt
Engine Under CoverPS Vane Pump
Oil Cooler Hose
for A/T Electric Cooling
Fan Connector
Upper Radiator
Hose
x 18
58 (590, 43)
52 (530, 38)
N´m (kgf´cm, ft´lbf)
 Non±reusable part: Specified torqueWire Clamp
Upper Radiator
Support
± COOLING (2JZ±GE)WATER PUMP
CO±3
1541 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
WATER PUMP
COMPONENTS

B01985
Water Bypass Outlet
 O±Ring
Engine Wire
Water
Pump
Connector Bracket
Idler PulleyGasket
Timing Belt GuideNo.2 Water Bypass Pipe
Drain Hose
Timing Belt Tensioner
Timing Belt
Drive Belt TensionerOil Filler Cap
No.3 Timing Belt Cover
No.1 Water
Bypass Pipe
 Gasket
Crankshaft PulleyDust Boot
x 5 Thermostat
 O±Ring
 O±Ring
No.2 Timing Belt Cover
Gasket
No.1 Timing Belt Cover
 Gasket
Water Inlet
x 6
35 (350, 26)
21 (210, 15)
21 (210, 15)
27 (270, 20)

N´m (kgf´cm, ft´lbf) : Specified torque
 Non±reusable part

Precoated part
330 (3,300, 243)
Clamp Bracket
Crankshaft Position
Sensor Connector
Gasket
CO±4
± COOLING (2JZ±GE)WATER PUMP
1542 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

CO09Z±03
A02725Turn
Loosen
B01614
Water Bypass Outlet
No.1 Water Bypass Hose
B01638
Clamp Bracket
Connector Bracket
B01572No.2 Water Bypass Pipe
± COOLING (2JZ±GE)WATER PUMP
CO±5
1543 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
1. REMOVE RADIATOR ASSEMBLY
(See page CO±18)
2. REMOVE DRIVE BELT AND WATER PUMP PULLEY
(a) Loosen the 4 nuts holding the water pump pulley to the
water pump.
(b) Loosen the drive belt tension by turning the drive belt ten-
sioner clockwise, and remove the drive belt.
(c) Remove the 4 nuts and water pump pulley.
3. REMOVE TIMING BELT AND IDLER PULLEY
(See page EM±16)
4. REMOVE WATER BYPASS OUTLET AND NO.1
WATER BYPASS PIPE
(a) Remove the 2 bolts, water bypass outlet and No.1 water
bypass pipe.
(b) Remove the 3 O±rings from the water bypass outlet and
No.1 water bypass pipe.
5. REMOVE WATER INLET AND THERMOSTAT
(See page CO±11)
6. REMOVE WATER PUMP
(a) Loosen the nut and remove the bolt, slide the generator
away from the water pump.
(b) Remove the bolt, and disconnect the clamp bracket (for
engine wire).
(c) Remove the bolt, and disconnect the connector bracket
(for crankshaft position sensor connector).
(d) Remove the 2 nuts, and disconnect the No.2 water by-
pass pipe from the water pump.

B01941
Drain Hose
CO±6
± COOLING (2JZ±GE)WATER PUMP
1544 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(e) Remove the 6 bolts, water pump and gasket.
(f) Remove the drain hose.
(g) Remove the O±ring from the cylinder block.

CO0A0±01
B01574
± COOLING (2JZ±GE)WATER PUMP
CO±7
1545 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
INSPECT WATER PUMP
Turn the pulley seat, and check that the water pump bearing is
not rough or noisy.
If necessary, replace the water pump.

CO0A1±03
P03945
New
O±Ring
P02574
New Gasket
A02801
AB A
B
A
B
B
B
B01614
New O±Ring
CO±8
± COOLING (2JZ±GE)WATER PUMP
1546 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSTALLATION
1. INSTALL WATER PUMP
(a) Install a new O±ring to the cylinder block.
(b) Install the drain hose.
(c) Install a new gasket to the water pump.
(d) Connect the water pump to the water bypass pipe. Do not
install the nut yet.
(e) Install the water pump with the 2 bolts (A) and 4 bolts (B).
Torque: 21 N´m (210 kgf´cm, 15 ft´lbf)
HINT:
Hand tighten the (A) bolts first.
(f) Install the 2 nuts holding the No.2 water bypass pipe to
the water pump.
Torque: 21 N´m (210 kgf´cm, 15 ft´lbf)
(g) Install the connector bracket (for crankshaft position sen-
sor connector) with the bolt.
(h) Install the clamp bracket (for engine wire) with the bolt.
(i) Install the generator with the bolt and nut.
Torque: 40 N´m (400 kgf´cm, 30 ft´lbf)
2. INSTALL THERMOSTAT AND WATER INLET
(See page CO±13)
3. INSTALL NO.1 WATER BYPASS PIPE AND WATER
BYPASS OUTLET
(a) Install 2 new O±rings to the No.1 water bypass pipe.
(b) Install a new O±ring and the water bypass outlet with the
2 bolts.
Torque: 9.0 N´m (90 kgf´cm, 80 in.´lbf)
4. INSTALL IDLER PULLEY AND TIMING BELT
(See page EM±23)
5. INSTALL WATER PUMP PULLEY AND DRIVE BELT
Torque: 14 N´m (140 kgf´cm, 10 ft´lbf)