Replacement [08/2015 - ]: Procedure

1. Remove the 4 screws and center No. 4 engine under cover.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Connect a hose with an inside diameter of 9 mm (0.354 in.) to the radiator drain cock as shown in the illustration.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *1	Engine Under Cover
   *a	Hose

2. Loosen the radiator drain cock plug.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *1	Radiator Drain Cock Plug	*2	Reserve Tank Cap
   *3	Water Filler Cap Sub-assembly	*4	No. 4 Radiator Hose
   *a	No. 2 Radiator Hose Sub-assembly	-	-

3. Remove the reserve tank cap and water filler cap sub-assembly. Then drain the engine coolant.

   HINT: 

   Collect the engine coolant in a container and dispose of it according to the regulations in your area.

4. Tighten the radiator drain cock plug by hand.
5. Disconnect the hose from the radiator drain cock.

1. Add engine coolant to the [AR] B line of the radiator reserve tank assembly. [*1]

   Specified Capacity

   7.8 liters (8.2 US qts, 6.9 Imp. qts)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	[AR] B line

   NOTE:

   • Do not reverse the position of the reserve tank cap and water filler cap sub-assembly when installing them. Doing so may damage the parts.
   • Do not substitute plain water for engine coolant.
   • Apply a light coat of engine coolant to the O-ring of the water filler cap sub-assembly when installing the water filler cap sub-assembly.

   HINT: 

   LEXUS vehicles are filled with TOYOTA SLLC at the factory. In order to avoid damaging the engine cooling system and other technical problems, only use TOYOTA SLLC or similar high quality ethylene glycol based non-silicate, non-amine, non-nitrite, non-borate coolant with long-life hybrid organic acid technology (coolant with long-life hybrid organic acid technology is a combination of low phosphates and organic acids).

2. Install the reserve tank cap.
3. Add engine coolant to the radiator pipe filler hole.
4. Install the water filler cap sub-assembly.
5. Squeeze the radiator hose sub-assembly and No. 2 radiator hose sub-assembly several times by hand, and then check the level of the engine coolant.

   If the engine coolant level is low, add engine coolant.

6. Bleed air from the cooling system. [*2]
   NOTE:

   • Before starting the engine, turn the A/C switch off.
   • Adjust the heater control to the maximum hot setting.
   • Adjust the blower speed to the low setting.
   1. Warm up the engine until the thermostat opens. While the thermostat is open, circulate the engine coolant for several minutes.

      HINT: 

      The thermostat open timing can be confirmed by squeezing the No. 4 radiator hose by hand, and sensing vibrations when the engine coolant starts to flow inside the No. 2 radiator hose sub-assembly.

   2. Squeeze the radiator hose sub-assembly and No. 2 radiator hose sub-assembly several times by hand to bleed air.
      WARNING:

      When squeezing the radiator hose sub-assembly and No. 2 radiator hose sub-assembly:

      • Wear protective gloves.
      • Be careful as the radiator hose sub-assembly and No. 2 radiator hose sub-assembly are hot.
      • Keep your hands away from the fan and No. 2 fan.
      NOTE:

      • Make sure that the radiator reserve tank assembly still has some engine coolant in it.
      • If the coolant temperature gauge indicates an excessive temperature, turn off the engine and let it cool.
      • If there is not enough engine coolant, the engine may overheat or be seriously damaged.
      • If the radiator reserve tank assembly does not have enough engine coolant, perform the following: 1) stop the engine, 2) wait until the engine coolant cools down, and 3) add engine coolant until the radiator reserve tank assembly is filled to the full line.
7. Stop the engine, and wait until the engine coolant cools down. [*3]
8. Check that the engine coolant level is between the full line and low line. [*4]

   HINT: 

   • If the engine coolant level is below the low line, repeat steps from [*1] to [*4].
   • If the engine coolant level is above the full line, drain engine coolant so that the engine coolant level is between the full line and low line.

Refer to PROCEDURE - Step 1

1. Install the center No. 4 engine under cover with the 4 screws.