VALVE GP-SELECTOR & PRESS CONT 6Y1179 - Caterpillar

Table 1
Required Tools    
Part Number    Description    Required Amount    
198-4240     Digital Pressure Indicator     1    
9T-6865     Adapter Plug     1    
5P-2937     O-Ring Adapter     1    
6V-3966     Fitting As     1    
Illustration 1 g00692584
Rear of Tractor (1) Plug in elbow
Illustration 2 g00987272
Sequence and Pressure Control Valve (Apron) (2) Bolts
Illustration 3 g00987275
Section View of Sequence and Pressure Control Valve (Apron) (2) Bolts (3) Shims (4) Relief valveThe sequence and pressure control valve for the apron is located on the right side of the scraper in the draft frame tube.
Operate the machine until the hydraulic oil reaches normal operating temperature.
Stop the machine on a hard, level surface. Move the transmission control lever to NEUTRAL. Lower the bowl. Stop the engine. Engage the parking brake.
Remove plug (1) .
Assemble the following components and connect to the open port: 9T-6865 Adapter Plug, 5P-2937 O-Ring Adapter and 6V-3966 Fitting As .
Connect 198-4240 Digital Pressure Indicator to the 6V-3966 Fitting As .
Start the engine. Run the engine at 1000 RPM in NEUTRAL.
Lower the bowl to the ground. Close the apron.
Slowly move the bowl control lever toward the RAISE position. As the bowl moves upward, the reading on the pressure gauge is the setting of the relief valve. Refer to Specifications, "Sequence and Pressure Control Valve (Apron)" for the correct pressure setting of the relief valve.
If the pressure setting requires adjustment, continue to Step 10. If the pressure setting is correct, continue to Step 18.
If it is necessary to change the setting of the relief valve, stop the engine.
Remove the plate on the right side of the draft frame tube.
Remove bolts (2) and the cover from the sequence and pressure control valve for the apron.
Remove relief valve (4) with the spring and shims (3). Remove shims (3) in order to decrease the pressure setting on the relief valve. Add shims (3) in order to increase the pressure setting of the relief valve. Refer to Specifications, "Sequence and Pressure Control Valve (Apron)" for the pressure change for one shim.
Install relief valve (4) with the springs and shims (3) .
Install the cover and bolts (2) for the sequence and pressure control valve for the apron.
Install the plate on the right side of the draft frame tube.
Repeat Steps 6 through 9.
Stop the engine. Remove all test equipment.
Install plug (1) .