TRENCHER AR 2618560 - Caterpillar

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, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Note: Use the information in the reference to prepare the machine for this test. Also, use the information in the reference to relieve any hydraulic pressure that may be in the steering system.ReferenceFor the correct procedure to relieve any hydraulic oil pressure that may be in the steering system, refer to the Service Manual module for Testing and Adjusting, "System Pressure - Release" for the machine that is being tested.
Table 1
Required Tools    
Part Number     Description    
8T-0860 (1)     Pressure Gauge    
( 1 ) The 198-4240 Digital Pressure Indicator is also available.The backup relief valve for the steering system is located on the steering control valve. The backup relief valve controls the pressure in the steering system in case the pressure control section of the steering pump fails.The backup relief valve for the steering system is set to a higher pressure than the maximum system pressure (pump stall pressure). Therefore, the backup relief valve only operates if the control section of the steering pump fails to regulate the pump pressure to 22800 700 kPa (3307 102 psi).Use the following procedure to check the pressure setting for the backup relief valve.
Illustration 1 g00460133
Steering Frame Lock in the LOCKED Position (1) Steering frame lock.
Move steering frame lock (1) to the LOCKED position.
Engage the parking brake. Move the transmission direction selector to the NEUTRAL position.
Attach a 0 to 40000 kPa (0 to 5800 psi) pressure gauge to a section of hydraulic line.
Illustration 2 g01099999
Location of hydraulic service center.
Illustration 3 g02448523
Right side view of the fan brake pilot manifold (2) Pressure tap for the steering pump
Attach the hydraulic line to pressure tap (2) . Pressure tap (2) is located on the right side of the machine in the hydraulic service center on the fan brake pilot valve.
Start the engine. The engine should be at high idle throughout the warm-up procedure. Continuously stall the TILT BACK position while simultaneously raising the lift arms at full speed. When the lift arms are almost raised, cycle the tilt cylinder to the FULL DUMP position. Then cycle to the TILT BACK position. Continuously stall the TILT BACK function and simultaneously lower the lift arms back to ground level. Without stalling the rack back function, cycle lift function to raise and lower the lift arms. This procedure will allow the pump to operate at low pressure and circulate oil through out the system. Repeat this procedure until the hydraulic oil is at 62° 8°C (143.6° 14.4°F).
After the oil has reached normal operating temperature, lower the bucket to the ground. Stop the engine.
Illustration