BOSS-WELD 8T3851 - Caterpillar

3408 (67U, 99U, 78Z)These fuel lines groups are for use on the above engines that are equipped with direct injection, turbocharger and aftercooler. These lines groups must be installed together. The fuel injection lines in the 5N5930 Fuel Injection Lines Group have a double wall (a tube within a tube) with a space between the two tubes. If there is fuel leakage from an inner fuel line, the outer fuel line will direct the leakage to the reservoir of the 2N9768 Switch, which is part of the 2W1788 Fuel Lines Drain Group. Use this instruction along with the Service Manual for the correct installation procedures. Any alarm or signal that is to be used with this switch must be purchased separately. The alarm or signal for fuel leakage and the 2N9768 Switch must both be connected into the alarm system for the ship, building, etc. Be sure to check the liquid level adjustment at which the 2N9768 Switch will activate to send a signal.5N5930 Fuel Injection Lines Group
(1) Remove former fuel injection lines (1) from each fuel injection pump to the adapters in the base of the valve mechanism cover. Remove the cover from the base. Remove the through-the-base adapter for each set of fuel lines. Put an 8M4437 Seal on each 1W6777 Adapter (2) and install the adapters in each bore where the adapters were removed. Use engine oil as a lubricant on the seals. Fasten the adapters to the cover base with the former nuts and two 5N5365 Locks on each. Connect former fuel lines (3) to adapters (2) and to the injector nozzles. (2) Install 2W2496 Bracket (4) and 2W2495 Bracket (5) where the former brackets were removed. Put a 5P9267 Seal on each injector pump and put a 2W2500 Washer (6) and 6V6579 Seal (7) on each adapter (2). Loosely install the fuel injection line assemblies that follow: 1W6318 (8), 1W6316 (9), 1W6313 (10), 1W6317 (11), 1W6315 (12), 1W6312 (13), 1W6314 (14) and 1W6311 (15). Tighten fuel injection line nuts (16) on each fuel line to 41 7 N m (30 5 lb.ft.) before cover nuts (17) are tightened. If the fuel lines have metal tags for part number identification, remove the tags before installation. Fasten tubes (8), (9), (12) and (15) together on the left side with four 2W2492 Clamps (18), 2W2493 Clamps and 310216 Bolts. Fasten the fuel lines to brackets (4) and (5) with 2W2492 Clamps (19), 2W2493 Clamps, 2W2494 Spacers, 1D4533 Bolts and 3B4504 Lockwashers. Fasten the fuel injection lines together on the right side with 2W2492 Clamps (20), 2W2493 Clamps and 310216 Bolts. Install four 2W2498 and 2W2499 Clamps on tubes (12) and (14) with 6V5370 Screws as shown.2W1788 Fuel Lines Drain Group
(1) Install a 9L8496 Tee (1) on each fuel line adapter (2). Install six 5N5940 Tube Assemblies (3) between tees (1) as shown. Install two 9L8492 Plugs (4). Install 2W3092 Tube Assembly (5), 2W3091 Tube Assembly (6) and 9L8557 Tee (7). Install 4M5317 Bushing (8)