COVER 2362502 - Caterpillar

3306 Truck EnginesDescription of Change: A new water temperature regulator is used that will help prevent engine overcooling on all 3306 Truck Engines. The new regulator has a rubber cover that will help prevent leakage around the regulator when it is closed. This leakage around a closed regulator can cause engine overcooling.Adaptable As: The new 4W1987 Water Temperature Regulator is a direct replacement for the former 7N208 Water Temperature Regulator when used with an 8N4485 Valve Assembly.To install the new regulator on earlier engines, it will be necessary to either use a 4W1986 Adapter between the elbow and cylinder head or make a modification to the cylinder head. The adapter is used as a housing for the 8N4485 Valve Assembly. Because of the thickness of the adapter, the height of the elbow will be increased approximately 19.0 mm (.75 "). To be able to use this adapter, the hose between the elbow and the radiator must be long enough and flexible enough to make the connection between the radiator and elbow after the adapter is installed. See Chart A for the parts that will be needed for installation of the new regulator and the adapter. Illustration 1 shows the location of these parts.
Illustration 1. Location of new parts.If the hose between the elbow and radiator is not long enough and/or flexible enough to use the adapter, it will be necessary to make a modification to the cylinder head. This modification will provide a hole for installation of the valve assembly
Use the procedure that follows to make the necessary modifications to the cylinder head.
1. Put a paper cloth in the hole for the water temperature regulator. Make sure the cloth is under the vent hole. This cloth is necessary to keep metal chips out of the cooling system.2. Drill and spotface the vent hole to the sizes shown in Illustration 2.3. Remove the paper cloth and metal chips from the cylinder head. Make sure the 8N4485 Valve Assembly will fit in this new hole. The top of the valve assembly must not extend above the surface of the cylinder head.Chart B shows the parts needed for installation of the new regulator when the modification is made to the cylinder head. See Illustration 2 for the location of these parts.
Illustration 2. Dimensions for the modification of the cylinder head and location of new parts.