HARDWARE GP 4940481 - Caterpillar

Sudden movement or accidental starting of the machine can cause personal injury or death to persons on or near the machine.To prevent personal injury or death, perform the following:Park the machine on a smooth, level surface.Lower the work tool to the ground and engage the parking brake.Stop the engine and remove the key.Block the wheels and install the steering frame lock.
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.
Machine Preparation
Reference: For information about preparing a machine for troubleshooting, refer to the Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.
Illustration 1 g00294371
Grill Assembly
Remove eight bolts (1) and grill (2) .
To check the speed of the fan drive motor, a 9U-7400 Multitach must be used. The multitach measures the speed of the fan drive motor by using reflective tape and a photo pickup. Reference: Special Instruction, NEHS0605, "9U-7400 Multitach II Group and 9U-7402 Multitach II Group"Note: If a piece of reflective tape is already visible on one of the fan blades, proceed to Step 107. If no reflective tape is visible on one of the fan blades, use the following procedure:
Illustration 2 g00292813
The hood has been removed for photographic purposes only.
Remove ten bolts (3) and move lower fan guard (4) in order to access the fan blades.
Clean a small area on the surface of one fan blade. Position the reflective tape so that the tape is completely visible. Then attach a piece of the tape to the fan blade.
Install lower fan guard (4). Install bolts (3) and tighten the bolts.
Illustration 3 g00294369
Placement of the 9U-7400 Multitach near the fan motor (5) Magnetic base. (6) Photo pickup. (7) Multitach.
Place photo pickup (6) into the holder on magnetic base (5) and tighten the screw. Attach magnetic base (5) to the fan guard assembly.
When the reflective tape and photo pickup (6) are in alignment, the LED indicator (red light) will come on. Position photo pickup (6) accordingly. To check for correct alignment, use a long, narrow object to reach through the fan guard and manually rotate the fan.Note: When you start the engine, vibration of the machine may cause the photo pickup to become misaligned. It may be necessary to adjust the position of magnetic base (5) in order to realign photo pickup (6) .Testing and Adjusting Fan Speed
Start the engine. Run the engine at high idle. Move the control levers in all directions in order to warm the hydraulic oil to normal operating temperature 49 to 65°C (120 to 150°F).Note: The temperature of the engine coolant must not exceed 70 °C (160 °F) when the fan speed is checked at low idle.
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Piston pump (Hydraulic