On-Vehicle Inspection

WARNING: This page is about a different car, the 2006 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.

CHECK RADIATOR CAP SUB-ASSEMBLY

Measure the valve opening pressure.

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

Fig 1: Checking Radiator Cap Operation
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Check that 1, 2 or 3 is not deformed, cracked or swollen.
Check that 3 and 4 are not stuck together.
Apply engine coolant to 2 and 3 before using the radiator cap tester.
When using the cap tester, tilt it more than 30 degrees.

Pump the cap tester several times, and check the maximum pressure*1.

Pumping speed: 1 pump per second

Fig 2: Checking Radiator Cap Using Radiator Cap Tester

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

*1: Even if the cap cannot maintain the maximum pressure, it is not a defect.

Judgment criterion

JUDGMENT CRITERION REFERENCE CHART

Item	Specified Condition
Standard valve (for brand-new cap)	93.3 to 122.7 kPa (0.95 to 1.25 kgf*cm² , 13.5 to 17.8 psi)
Minimum standard valve (for used cap)	78.5 kPa (0.8 kgf*cm² , 11.4 psi)

If the maximum pressure is less than the minimum standard valve, replace the radiator cap sub-assembly.