Engine

On-vehicle inspection

~1min read

1. CHECK RADIATOR RESERVOIR CAP SUBASSEMBLY

Check radiator reservoir cap subassembly

a) Measure the valve opening pressure.

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

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

(3) Check that rubber packings 3 and 4 are not stuck together.

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

(5) When using the cap tester, tilt it to 30° or more above the horizontal.

(6) Pump the cap tester several times, and check the maximum pressure*.

Pump speed: 1 pump per second

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

Check radiator reservoir cap subassembly

Judgment criterion

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

Test yourself

A quick Toyota Sienna quiz: every answer comes with an explanation and a link to the manual page.