BAR ASSEM. 6D3337 - Caterpillar

Introduction
This Special Instruction describes two procedures for improving fuel priming pump performance on machines listed above equipped with certain 3500 engines.The first procedure is referred to as the "Good" solution and is most likely to be performed in the field. Refer to Table 1 for the "Good" solution parts list.The second procedure is referred to as the "Better" solution and is most likely to be performed during engine rebuild. Refer to Table 2 for the "Better" solution parts list.Parts Needed
Table 1
Good Solution    
Qty    New Part    
1     238-5080 O-Ring Seal    
1     238-5081 O-Ring Seal    
1     305-6991 Elbow    
1     420-1796 Check Valve    
2     436-8983 Check Valve    
Table 2
Better Solution    
Qty    Part    
1     235-8725 Fuel Transfer Pump and Filter Gp    
1     238-5080 O-Ring Seal    
1     238-5081 O-Ring Seal    
1     305-6991 Elbow    
1     420-1796 Check Valve    Rework 1 "Good" Solution
Illustration 1 g03587797
Typical 217-6927 Fuel Priming Pump and Primary Filter Gp (1) 436-8983 Check Valve (2) 179-7267 Plug
Drain the fuel from the fuel priming pump and primary filter group into a suitable container for storage or disposal.
Remove two plugs (2) from the fuel priming pump and primary filter group.
Remove and discard the two 162-2220 Check Valves .
Install one check valve (1) per port into the fuel priming pump and primary filter group.
Reinstall two plugs (2) into the fuel priming pump and primary filter group.
Illustration 2 g03603597
Typical 217-6927 Fuel Priming Pump and Primary Filter Gp (3) 305-6991 Elbow (4) 238-5081 O-Ring Seal (5) 420-1796 Check Valve (6) 238-5080 O-Ring Seal
Remove the fuel line from the existing elbow.
Remove the existing elbow from the fuel priming pump and primary filter group.
Install elbow (3) and one O-ring (4) into the fuel priming pump and primary filter group.
Install check valve (5) and one O-ring (6) into elbow (3) .
Attach the original fuel line to check valve (5) .Rework 2 "Better" Solution
Illustration 3 g03587857
(1) 217-6927 Fuel Priming Pump and Primary Filter Gp (2) 235-8725 Fuel Transfer Pump and Filter Gp
Drain the fuel from fuel priming pump and primary filter group (1) into a suitable container for storage or disposal.
Remove the fuel lines from fuel priming pump and primary filter group (1) .
Remove fuel priming pump and primary filter group (1) from the engine.
Install fuel transfer