GUARD AS 2057895 - Caterpillar

Personal injury or death can result from sudden machine movement.Sudden movement of the machine or release of air pressure or oil pressure can cause injury to persons on or near the machine.To help prevent possible injury before testing and adjusting any air system or hydraulic system, perform the procedure in the Testing and Adjusting, "General Information" section.
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.Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines.Dispose of all fluids according to local regulations and mandates.
Illustration 1 g00296295
Steering Pump (1) Pressure and flow compensator valves.
Illustration 2 g00296296
View A-APressure and Flow Compensator Valves (2) Signal pressure port. (3) Adjustment screw for the margin pressure. (4) Adjustment screw for the pressure cutoff.Pressure and flow compensator valves (1) can be replaced or adjusted. If the pressure and flow compensator valves do not respond to adjustment, the problem is with the steering pump. If the standby pressure is still high after replacing a pressure and flow compensator valve, the problem is with the steering pump.The cutoff pressure of the two steering pumps is approximately equal to 29000 kPa (4200.0 psi).Note: The pressure setting of the steering system relief valve is approximately equal to 31000 kPa (4500.0 psi). This relief pressure setting can not be checked by installing the steering frame lock, and then checking the steering pressure as the machine is being steered.In order to check the relief valve setting for the steering system, use the following steps:
Connect a 51675 kPa (7500.0 psi) pressure gauge to the pressure tap that is located at each steering pump.
Install the steering frame lock in order to prevent the machine from articulating.
Start the engine. Run the engine at low idle.Note: Adjustment screws (3) and (4) for the pressure and flow compensator valves are sealed. Do not attempt to adjust the pressure and flow compensator valves until all of the other possibilities for the system malfunction have been checked. You should be familiar with the operation of the steering pumps and the controls for the steering pumps. Mark the position of the adjustment screw before making any adjustment. This will allow you to return the adjustment screw to the original position if it is necessary.
While the STIC is being moved to the left or to the right, look at the gauge that was installed in Step 1, and adjust screw (4) for the maximum pressure cutoff. Turn the adjusting screw inward until the pressure gauge does not show any increase in pressure. This is the relief valve setting for the steering system. The relief valve setting should be approximately equal to 31000 kPa (4500.0 psi).Do not overheat the steering oil.Return the adjusting screw to the original position. The pressure should now be approximately equal to 29000