PISTON 1630326 - Caterpillar

Personal injury can result from hydraulic oil pressure and hot oil.Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.
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.
Before you begin the following procedure, refer to Testing and Adjusting, "Machine Preparation for Troubleshooting".
Table 1
Required Tools    
Tool    Part Number    Description    Qty    
A     198-4240     Digital Pressure Indicator     1    
B     6V-8556     Nut     1    
C     6V-8558     Face Seal Nut     1    
D     6V-8941     Reducer     1    
E     6V-8947     Reducer     1    
F     7X-2429     Swivel Tee     1    
G     126-0814     Fitting As     1    The main relief valve is installed in the main control valve for the scraper. The main relief valve is located near the oil line connection from the pump.
Stop the machine on a hard, level surface. Move the transmission control lever to NEUTRAL. Lower the bowl. Stop the engine. Engage the parking brake.
Illustration 1 g01010938
Disconnect hose (2) from elbow (1) .Note: The opposite end of hose (2) is connected to the pump for the implements.
Assemble the following components: Tool (F), Tool (E), Tool (C), Tool (D), Tool (B) and Tool (G). Install the assembly between elbow (1) and hose (2) .
Connect Tooling (A) to Tool (G) .
Start the engine. Run the engine at HIGH IDLE in NEUTRAL. Allow the hydraulic oil to reach normal operating temperature.
Cycle the ejector in order to bleed the air from the hydraulic system.
Move the ejector control lever to the RETURN position in order to retract the ejector. Release the ejector control lever.
Hold the ejector control lever in the RETURN position. The reading on the pressure gauge is the pressure setting of the main relief valve. Refer to Specifications, "Relief Valve (Main)" for the pressure setting of the main relief valve.Note: Do not hold the ejector control lever in the RETURN position for more than 5 seconds.
If the pressure setting requires adjustment, continue to Step 10. If the pressure setting is correct, continue to Step 14.
If it is necessary to change the setting of the main relief valve, stop the engine.
Illustration 2 g01006466
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