CONTROL GP-PRESSURE 6W8587 - Caterpillar

Industrial Engines (7C6614 Arr't) In Driltech Drill RigsSUPPLEMENT: 06/00/87ENGINE NEWS, MAY 1987, PAGE 13, "Serviceable Parts For New Fuel Ratio Control; Pressurize Control To Set Rack On 3406B Engines In Driltech Drill Rigs".(Supplement Applies Only To 3406B Engines In These Oil Rigs). On Page 13, the last paragraph contains an incorrect "FT" part number. The correct number for the fabricated test kit to pressurize the control is "FT1906".
--------------- END SUPPLEMENT ---------------A new 7W5318 Fuel Ratio Control Assembly is now used on 3406B Industrial Engines with the 7C6614 Engine Arrangement in Driltech Drill Rigs. This control is mechanically simpler and costs less than the former control. This new control is also used in other nonindustrial engine applications.
Parts Books and microfiche do not include the new parts in the fuel pump and governor groups that use the new fuel ratio control. These parts are shown in the following illustrations. Write a reference note by these groups in the affected Parts Book to refer to this article.
Illustration 1. New parts in the governor and fuel injection pump group.If service work is done on the new control, there are two differences to remember that apply only to the drill rig application.
... The control must be pressurized to 105 kPa (15 psi) in order to check the static fuel setting. This can be done with air pressure and a suitable pressure regulating valve. Or, the fabricated test kit (FT1829) can be used.
Illustration 2. New linkage and parts in the governor group (internal view of governor lever where connected to the new control). The parts shown are different than for other applications of this new fuel ratio control.... Also, in the governor linkage, a special 7C8219 Lever Assembly is used. See Illustration 2. This lever assembly uses a 7C8220 Piston and has NO spring. These changes inside the governor cause the maximum fuel setting at startup and during low boost to be limited to the fuel ratio control setting. These changes also help engine starting in this application.A Service Manual Supplement will cover system operation, testing and adjusting, and disassembly and assembly of the control linkage. Individual parts of the new control assembly are not serviced.