VALVE GP-RELIEF 1803178 - Caterpillar

3304 Machine Engines (07Z),
3304 Industrial Engines (10E),
3304 Generator Set Engines (83Z),
3306 Industrial Engines (64Z),
3306 Generator Set Engines (2AJ, 85Z),
3306 Truck Engines (63Z)Description of Change: Improved fuel injection line assemblies and clamps are used. The improved lines are manufactured from a stronger material that is more resistant to cracking caused by vibration and high injection pressures. A new stepped washer (collar) is used at each end of the improved line assemblies. The collars provide more support to each end of the lines. The improved fuel line assemblies can be identified by the undercut on the hex nut at each end of the line.Adaptable To: The new components for 3306 fuel injection lines are identified in Illustration 1 and Chart A. The new components are in effect with 3306 Industrial Engine 64Z12452, 3306 Generator Set Engines 2AJ662, 85Z8778, and 3306 Truck Engine 63Z22117. The new components for 3304 fuel injection lines are identified in illustration 2 and Chart B. The new components are in effect with 3304 Machine Engine 07Z27991, 3304 Industrial Engine 10E3867, and 3304 Generator Set Engine 83Z6908.
Before removing any clamps, mark their location with tape or some other non-damaging method. This will help insure that the clamps are reinstalled in the correct locations. Use a 6V6069 Torque Screwdriver or similar tool to tighten the clamp screws to a torque of 2.25 N m (20 lb in). Do not force fuel injection line ends into position and then begin to tighten the nuts on the ends of the lines. The result will be added strain on the lines. If needed, gently bend the lines by hand until the lines are the correct shape for the nuts to be easily started. Before tighten the nuts on the ends of the fuel injection lines, use the fuel priming pump to purge air from the fuel system. Tighten the fuel injection line nuts to a torque of 40 7 N m (30 5 lb ft). After starting the engine and checking for leaks, tighten the fuel injection line nuts again to a torque of 40 7 N m (30 5 lb ft).
Illustration 1. Location of new 3306 fuel injection line components. Collar (X). Undercut Nut (Y).
Illustration 2. Location of 3304 fuel injection line components. View from top of engine.