Check Radiator 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 *1. Pumping speed: 1 pumps every second

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


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 (after using cap)

78.5 kPa (0.8 kgf/cm2, 11.4 psi)

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

Was this article helpful?

0 0
Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

Get My Free Ebook

Post a comment