RELIEF VALVE GROUP 2458355 - Caterpillar

Illustration 7 g00757590
Main Hydraulic Pressure Tap Location (21) Implement pump. (22) Pressure tap.
Attach a hose assembly onto pressure tap (22) that is shown in Illustration 7. Attach the hose assembly to the 8T-0852 Pressure Gauge (0 to 40,000 kPa (0 to 5,800 psi)).
Illustration 8 g00758295
Auxiliary Pressure Test Location (23) Cover. (24) M10 x 1.5 Bolts. (25) Plate assembly. (26) Connector. (27) Coupler assembly. (28) Pressure gauge.
Illustration 9 g00757584
938G Wheel Loader Tilt Cylinder (29) Location for the installation of the plate assembly and pressure gauge.
Illustration 10 g00758299
IT38G Integrated Toolcarrier Tilt Cylinder (30) Location for the installation of the plate assembly and pressure gauge.
Install an 8T-0859 Pressure Gauge from an 8T-5320 Hydraulic Test Group on an auxiliary cylinder or the tilt cylinder.Note: If no pressure taps are available, you can use the plate assembly that is shown in Illustration 8.
Table 2
Line Relief Valve Pressure Settings    
Cylinder     Head End     Rod End    
Tilt (IT38G)    
9000 350 kPa (1300 50 psi)    
25900 350 kPa (3750 50 psi)    
Tilt (938G)    
25900 350 kPa (3750 50)    
22100 350 kPa (3200 50 psi)    
Auxiliary    
22100 350 kPa (3200 50 psi)    
22100 350 kPa (3200 50 psi)    
Pin Coupler    
22100 350 kPa (3200 50 psi)    
22100 350 kPa (3200 50 psi)    
Table 3
Main Relief Valve Settings    
938G and IT38G    
24800 300 kPa (3600 45 psi)    Note: The pressure setting for the main relief valve must be above the pressure setting for the line relief valve in order to correctly set line relief valve pressure. Refer to Table 3 for the main relief valve setting.
Use Table 2 in order to determine the line relief setting for the machine that is being serviced. Compare the line relief valve pressure setting to the main relief valve setting.
Start the engine.
Raise the bucket or the work tool off the ground. Tilt back the bucket or the work tool until the cylinder rods are fully retracted or extended. The position of the cylinder rod (rods) will depend on the machine that is being tested.Note: In the following steps, do not keep the tilt control lever in the ENGAGED position for more than five seconds while the pressure is at the line relief valve pressure setting. This may cause rapid heating of the hydraulic oil.
Increase the engine speed to high idle. Move the tilt control lever to the TILT BACK position. Record the readings from the pressure gauges. Compare the pressure gauge readings with the specifications in Tables 2 and 3. Note: If the pressure setting for the main relief valve is lower the pressure setting for the line relief valve, temporarily increase the pressure setting for the main relief valve. For additional information on adjusting the pressure setting for the main relief valve, refer to Testing and Adjusting, "Relief Valve (Main) - Test and Adjust" for the machine that