CABLE AS 4332475 - Caterpillar

General Information
Springs
To make identification of the springs in the fuel ratio control easier, they have color codes (marks) on them. The springs currently used and their color codes are shown in Chart C. See the Parts Books for the part numbers of the spring used in your application.
Valve Assembly
There has been a problem with burrs on some of the former valve assemblies. These burrs can cause a restriction in the movement of the valve assemblies.
To check the operation of the valve assembly and the internal valve, the internal valve must be moved in the same direction as it moves when installed on the engine, towards the governor. If the operation is checked by movement of the internal valve in the opposite direction, the indication will be that the valve does not operate correctly even if the valve is in good condition. This is because of the sharp edges of the oil groove, not a burr.
Illustration 1. Location of new parts in fuel ratio control group.Some servicemen have at times ground the ends of the 2P8939 Valve (internal) to try to improve the alignment of the opening in the internal valve with the holes in the valve assembly. This modification is not necessary, because the holes do not control the amount of oil that will drain. The groove in the valve assembly controls the amount of oil. Any improvement in performance after this modification was probably from the use of a new diaphragm, seals or adjustments.
Also, reports show that the letters "PC" on the end of the 2P8802 Valve Assemblies have caused some confusion (problems). These letters are for identification purposes only. They do not mean that the valve assembly must be used only in a precombustion chambered engine. The 2P8802 Valve Assemblies with the letters "PC" are correctly used in several direct injection engines. If desired, the "PC" mark can be removed from the end of the valve assemblies to prevent any confusion in the future.
Diaphragm
Formerly, the 2P8804 (Black) and 1W4797 (Gray) Diaphragms were used. The former black diaphragm can become rigid and possibly crack. This can cause a loss of boost and slow action of the fuel ratio control. The former gray diaphragm has been found with oil in the air chamber. This was caused by leakage around the retainer assembly. This small amount of oil leakage will not decrease engine performance, unless it is the result of a damaged diaphragm.
Tests For Fuel Ratio Control
The diaphragm, covers and gaskets can be checked for air leakage and the fuel ratio control can be checked for correct movement while the fuel ratio control group is still on the machine. To make these checks, it will be necessary to fabricate a tool group as shown in Illustration 2. To check the diaphragm, covers and gaskets for air leakage, use the procedure which follows.
The engine can be stopped or running for these checks.
Illustration 2. Parts needed for fabricated tool group.1. Disconnect the boost (air) line for the fuel ratio control