RAIL-BULK 4801844 - Caterpillar

Personal injury can result from hydraulic oil under pressure.Hydraulic oil under pressure can cause injury to persons on or near the machine when the pressure is suddenly released.At operating temperature, the hydraulic oil tank is hot and under pressure. Hot oil can cause burns.Remove the fill plug only when the engine is stopped, and the fill plug is cool enough to touch with your bare hand.Do not allow hot oil or components to contact skin.
Personal injury can result from spring force released when removing cap screws.Internal spring force will be released when cylinder assembly cap screws are removed causing injury.Always restrain cover as cap screws are loosened.Follow the established procedure in the Service Manual to service these parts.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Dispose of all fluids according to local regulations and mandates.
Refer to the Systems Operation, Testing and Adjusting, "Machine Preparation for Troubleshooting".The main relief valve regulates the working pressure to each of the implements (Apron, Ejector, and Bowl). The main relief is located on the implement control valve. The implement control valve is located on the draft frame of the scraper. Perform the following procedure in order to check the pressure of the main relief valve.
Table 1
Required Tools
Tool Part Number Description Qty
A 198-4240 Digital Pressure Indicator 1
Illustration 1 g02859596
Illustration 2 g02859582
Close up view of the implement control valve
Remove the dust cap from test port (2) on implement control valve (1) and attach tooling (A).
Start the engine. Run the engine at high idle.
Raise the bowl to the fully raised position. Hold the joystick in the bowl RAISE position.
Check the pressure at test port (2). The correct pressure setting is 14000 600 kPa (2030 87 psi). Set main relief valve (3) in order to obtain the correct pressure setting.
Illustration 3 g01430027
To change the setting of main relief valve (3), loosen nut (5) and turn retainer assembly (4). One complete turn of retainer assembly (4) will change the pressure approximately 7000 kPa (1015 psi). Turning the retainer assembly (4) clockwise will increase the setting. Turning the retainer assembly (4) counterclockwise will decrease the setting. Tighten the nut (5) after the correct setting is established.
When you have completed the test, remove the test equipment from the machine.