Check valve seat (A) of radiator cap.

B : Metal plunger

- Check that valve seat is swollen to the extent that the edge of the plunger cannot be seen when watching it vertically from the top.

- Check that valve seat has no soil and damage.

Pull negative-pressure valve to open it, and that it close completely when released.

- Check that there is no dirt or damage on the valve seat of radiator cap negative-pressure valve.

- Check that there are no unusualness in the opening and closing conditions of negative-pressure valve.

• Check radiator cap relief pressure.

Standard and Limit : Refer to CO-54, "Radiator".

- When connecting radiator cap to the radiator cap tester (commercial service tool) (A) and the radiator cap tester adapter (commercial service tool) (B), apply engine coolant to the cap seal surface.

• Replace radiator cap if there is an unusualness related to the above three.

CAUTION:
When installing radiator cap, thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.