CAP AS-TRACK IDLER 4521402 - Caterpillar

--------------- END SUPPLEMENT ---------------New fuel injection pump groups are used. These new groups include new 7E5888 Fuel Pump Housing (1). This housing has larger diameter fuel pump camshaft bores. This allows the use of new camshaft (2) with a larger camshaft lobe base circle. New lifter assembly (3) and new plunger (4) and barrel (5) assembly are shorter to accommodate the new camshaft. Earlier longer plunger and barrel assemblies and lifter assemblies will not work with the new camshaft.
Illustration 1. Location of new components in fuel injection pump groups. Housing (1). Camshaft (2). Lifter Assembly (3). Plunger (4). Barrel (5). Bonnet (6). 7E4847 O-Ring Seal (7). Bushing (8).The shorter plunger and barrel assembly may contain a single or double scroll plunger. (See the Illustration 2.) Any fuel injection pump group that uses 4P7681 Fuel Injection Pump Groups, may have any combination of single or double scroll 7E6007 Plunger and Barrel Assemblies. This mixture of single and double scroll plungers will not affect the engine performance. The second scroll helps hydraulically balance the plunger.
Illustration 2. End view of 7E6007 Plungers (4). Single scroll plunger (A). Double scroll plunger (B). Shut-off slot (C).New 7E4847 O-Ring Seal (7) is used between bonnet (6) and bushing (8). The new seal has a blue teflon coating to help prevent the seal from being damaged during installation. The new seal replaces the former 6V5393 O-Ring Seal.
The new components, when used together, are adaptable to the Fuel Injection Pump Groups that follow: