GENERATOR AR 1304711 - Caterpillar

Hydraulic oil pressure can remain in the hydraulic system on this machine after the engine and pump have been stopped. Serious injury can result if this pressure is not released before any service is done on the hydraulic systems. In order to prevent possible injury, release the hydraulic system pressure before working on any fitting, hose, or hydraulic component.Lower all attachments to the ground before service is started. If the hydraulic system must be serviced, tested, or adjusted with the attachment in the raised position, the attachments and lift cylinders must be supported properly.Always move the machine to a location away from the travel of other machines. Be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being made.
High hydraulic system pressure. To avoid personal injury, do not remove any hydraulic system lines, taps, or parts until all pressure has been relieved.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. 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 on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Keep all parts clean from contaminants.Contamination of the hydraulic system with foreign material will reduce the service life of the hydraulic system components.To prevent contaminants from entering the hydraulic system, always plug or cap the lines, fittings, or hoses as they are disconnected. Cover any disassembled components and clean them properly before assembly.Clean the hydraulic system properly after any major component exchange or especially after a component failure, to remove any contamination.
The following procedures are performed on the right charge relief valve. Repeat the same procedures for the left charge relief valve.
Illustration 1 g01076336
Table 1
Required Tools    
Tool    Item    Part Number    Description    Qty    
A     A1     6V-4143     Coupler     2    
A2 6V-3989     Fitting     1    
A3 8T-0855     Pressure Gauge (
4000 kPa (580 psi))     1    
A4 177-7860     Hose As     1    
Illustration 2 g01076348
Open the right access door (1) .
Illustration 3 g01078680
Attach Tooling (A) to the charge relief valve test port.
Start the engine and run the engine at low idle.
Activate the parking brake.Note: The oil in the hydraulic system must be at an operating temperature of approximately 38 °C (100 °F).
Run the engine at high idle.
Run the left hand right feeder.
Observe the pressure gauge reading. The pressure should be approximately 2515 105 kPa (365 15 psi).
Illustration 4 g01078681
If the pressure reading was not correct, the charge relief valve needs adjustment.
Run the engine at low idle.
Stop the engine.
Remove charge relief valve (2) from the piston pump with the 1 inch combination wrench.
Inspect charge relief valve (2) for foreign material or wear.
Remove 077-3775 Shim from charge relief valve (2) or add