Cooling System - Leaks/Overheating

Classification:
EM04-003

Reference:
ITB04-007

Date:
February 6, 2004

RADIATOR CAP INSPECTION DURING COOLANT SYSTEM SERVICE

APPLIED VEHICLES:
All 1999 and Later Vehicles

IF YOU CONFIRM:
An applied vehicle has any of the following symptoms:
^ Leaking radiator
^ Overheating cooling system

OR

If you removed the radiator cap for any other reason.

ACTION:





^ Look for a "swollen" (enlarged) radiator cap gasket. See Figure 1a and 1b.

^ An enlarged radiator cap gasket can cause the cap to not vent properly. This can result in coolant loss and overheating.

^ See the Service Procedure on page two for more details.

PARTS INFORMATION

See the "FAST" parts system for the Radiator Cap applicable to the vehicle you're working on.

SERVICE PROCEDURE

During normal scheduled maintenance or for a vehicle with one of the symptoms listed under IF YOU CONFIRM inspect the Black Rubber Gasket on the end of the Metal Plunger of the radiator cap. View the Black Rubber Gasket by looking at the bottom side of the radiator cap.





A. The Black Rubber Gasket should be smaller in diameter than the Metal Plunger under it (see Figure 2).

If the Metal Plunger can be seen around the edge of the Black Rubber Gasket and the gasket is clean without any deposits of a waxy residue or foreign material the gasket is OK.

NOTE:
Make sure you pressure test the radiator cap and confirm it opens and closes at the correct specifications.





B. If the Metal Plunger cannot be seen around the edge of the Black Rubber Gasket (see Figure 3) the radiator cap must be replaced.
^ Thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.

^ Install a new radiator cap.





C. If the Metal Plunger can be seen around the edge of the Black Rubber Gasket but there are deposits of waxy residue or foreign material on the gasket or the metal retainer (see Figure 4) the radiator cap must be replaced.

^ Thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.

^ Install a new radiator cap.