Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: On-vehicle Inspection

ON-VEHICLE INSPECTION

CAUTION / NOTICE / HINT

CAUTION:

Do not remove the radiator cap sub-assembly while the engine and radiator assembly are still hot. Pressurized, hot engine coolant and steam may be released and cause serious burns.

PROCEDURE

1. CHECK RADIATOR CAP SUB-ASSEMBLY

CAUTION:

Do not remove the radiator cap sub-assembly while the engine and radiator assembly are still hot. Pressurized, hot engine coolant and steam may be released and cause serious burns.

(a) Measure the valve opening pressure.

(1) If there are water stains or foreign matter on the rubber packings (1), (2) or (3), clean the part(s) with water and finger scouring.

(2) Check that the rubber packings (1), (2) and (3) are not deformed, cracked or swollen.

(3) Check that the rubber packing (3) and valve seat are not stuck together.

(4) Apply engine coolant to the rubber packings (2) and (3) before using the radiator cap tester.

(5) When using the radiator cap tester, tilt it upward 30° or more.

(6) Pump the radiator cap tester several times, and check the maximum pressure. Pumping Speed: 1 pump per second HINT: Even if the radiator cap sub-assembly cannot maintain the maximum pressure, it is not a defect. Result: Item Specified Condition Standard pressure (for brand-new radiator cap sub-assembly) 93 to 123 kPa (0.9 to 1.3 kgf/cm2, 13.5 to 18.0 psi) Minimum pressure (for used radiator cap sub-assembly) 79 kPa (0.8 kgf/cm2, 11.5 psi) If the maximum pressure is less than the minimum pressure, replace the radiator cap sub-assembly.

*1 Radiator Cap Sub-assembly *a Radiator Cap Tester *b 30° or more

2. INSPECT FINS FOR BLOCKAGE

(a) If the fins are clogged, wash them with water or asteam cleaner and dry them with compressed air.