WASHER 5J8980 - Caterpillar

G3508 (4WD, 2JF, 9TG),
G3512 (4KC, 5JD, 7NJ),
G3516 (3RC, 8LD, 4EK, 5PN) EnginesA change was made to the 7E-1598 Mixer Assembly and valve in the carburetor groups identified in the chart. The part number of the mixer assembly did not change. In the earlier mixer assembly, (see Illustration 1) two screws (2) fastened the bottom part of the piston (3) to the top of the piston (1). In the current mixer assembly, (see Illustration 2) screws are not used to fasten the bottom of the piston (5) to the top (4). Instead, the valve alone is used to fasten the bottom of the piston to the top of the piston and an O-ring retaining plate.
Some carburetor groups that include the earlier mixer assembly, (see Illustrations 3 and 4) include a washer (6) that goes between the valve (7) and the bottom of the mixer piston (3). Carburetor groups that include the new mixer assembly, do not include a washer between the bottom of the piston and top of the valve (see Illustrations 6 and 7).
The valves (7) used with the earlier mixer assembly have a shallow relief area (C) on the top (see Illustration 5). Valves used with the new mixer assembly have a flat top (see Illustration 8). If valves with the relief area are used with the new mixer assembly and the new piston design, the raised edge may cause the O-ring retaining plate to be distorted. If a new mixer assembly is purchased to service existing mixer assemblies, it will have the new piston design and will require a flat topped valve to be used. If the existing valve used a washer (6), be sure to remove it before installing the new valve. See the chart to determine the correct valve to be used with the new mixer assembly.
Illustration 1. (EARLIER 7E-1598 Mixer Assembly)Top part of piston (1). Screws (2). Bottom part of piston (3).
Illustration 2. (CURRENT 7E-1598 Mixer Assembly)Top part of piston (4). Bottom part of piston (5).
Illustration 3. (TYPICAL CARBURETOR GROUP WITH EARLIER 7E-1598 Mixer Assembly).
Illustration 4. (DETAIL A) Bottom of piston (3).Washer (6).Valve (7).
Illustration 5.Cross section of valve (7) used with earlier mixer assembly. Shallow relief area (C).
Illustration 6. (TYPICAL CARBURETOR GROUP WITH CURRENT 7E-1598 Mixer Assembly).
Illustration 7. (DETAIL B)Bottom of piston (5).Valve (8).
Illustration 8.Cross section of valves (8) used with current mixer assembly.Flat top (D). When replacing the former gas valve with a new gas valve, be sure to remove the 7E-1569 Washer (6) in Illustration 4. The new 7E-1598 Mixer does not include the 7E-1569 Washer.