966M XE and 972M XE Wheel Loaders Power Train, Steering, Braking, Hydraulic, and Machine Systems Caterpillar

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Personal injury or death can result from machine articulation or movement. Machine frames can move and a person can be crushed. Connect the steering frame lock link between the front and rear frames before working on machine.

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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.

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Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact the skin.

Specifications

The recommended level of cleanliness for the hydraulic system is ISO Code 18/15. Refer to Table 1 for the maximum allowable particle count.

Note: The concentration of the particles by size should be monitored over a series of samples. This information can be used in order to spot abnormal wear before a failure occurs. A spectrographic analysis of the samples can be used in order to identify the composition of the particles. The analysis of the oil sample may be used in order to identify the components that are failing.

Introduction

The hydraulic oil in this system is SAE 10. If the hydraulic oil becomes contaminated, premature component failure could result. Contaminated hydraulic oil can also contribute to overheating.

Use the following procedure in order to sample the hydraulic oil.

Required Tools

Test Preparation

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Illustration 1	g02699498

1. Install the steering frame lock in the LOCKED position.

2. Start the engine. Operate the engine at high idle. Continuously stall the RACK BACK function while simultaneously raising the lift arms at full speed. When the lift arms are almost raised, cycle the tilt cylinder almost to the FULL DUMP position. Then move the tilt cylinders to the full RACK BACK position. Continuously stall the RACK BACK function and simultaneously lower the lift arms back to the ground level position. Without stalling the RACK BACK function, cycle the lift function to raise the lift arms fully. Then lower the lift arms in order to allow the pump to operate at low-pressure briefly and circulate oil through the system. Repeat this process in order to increase the temperature of the oil to normal operating temperature.

3. Operate the machine for a few minutes before you obtain the oil sample. This step will thoroughly mix the oil for a more accurate sample.

4. Lower the work tool to the ground.

5. Turn the engine start switch to the OFF position.

6. Turn the key start switch to the ON position. Move all control levers, brake pedals, and steering wheel through all positions in order to release any pressure in the hydraulic system.

7. Slowly remove the hydraulic tank cap In order to release the pressure in the hydraulic tank.

   Reference: For additional information about the release of hydraulic oil pressure, refer to Testing and Adjusting, "System Pressure - Release" for the machine that is being serviced.

8. Ensure that the control levers are in the HOLD and FLOAT positions.

Test Procedure

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Illustration 2	g03691420
Location of the Oil Sampling Port on the left rear of the machine (1) Oil Sampling Port

Note: Only perform a bottle sample when the system pressures are below 3450 kPa (500 psi). Prepare all equipment used to sample oil and protect the equipment from contamination.

1. The oil sampling port (1) is located on the left side rear of the machine.

   Reference: Refer to Special Publication, PEHP6001, "How To Take A Good Oil Sample" for more information about obtaining an oil sample.

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   Illustration 3	g01281559
   Sample bottle package

2. Open the 169-8373 Sample Bottle package. Remove the sampling probe tube from the bag.
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   Illustration 4	g01281560
   Probe holder and probe

3. Insert the open sampling probe tube into and through the 162-8873 Sample Bottle Probe Holder counter bored end. Pull the probe tube all the way through the holder until the sampling needle seats in the holder.
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   Illustration 5	g01281561

4. Remove the sampling bottle from the package. Install the cap with two holes onto the bottle. Install the probe tube into one of the holes in the cap.
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   Illustration 6	g01281562

5. Return the assembled bottle and return the probe back into the package in order to prevent contamination.

6. Exercise the machine until the system oil to be sampled is up to normal operating temperature or at a minimum of 50 °C (120 °F).

7. Park the machine on level ground. Lower all the attachments. Engage the parking brake.

8. Set the engine at low idle. Make sure that all systems are in safe positions. Refer to the Operation and Maintenance Manual.

9. Remove the dust cover from the S·O·S valve.

10. Clean the S·O·S valve with a clean 162-5791 Lint Free Shop Towel.

11. Purge the S·O·S valve by pressing the 8T-9208 Purge Probe onto the S·O·S valve. Purge a minimum of one sample bottle of oil or more. More than one sample may be required to ensure all the dead volume of the fluid is purged and the sampling nipple is internally cleaned.

12. Properly dispose of the purged oil.

13. Remove the prepared sample bottle from the package.

14. Rinse the sample bottle and rinse the probe tube with the system oil. Rinse the bottle by filling the bottle half full with the system oil.

15. Shake the sample bottle vigorously for several seconds.

16. Then empty the oil into a waste oil container.

17. Fill the sample bottle to the "fill range" imprinted on the bottle, but do not fill beyond the fill mark.

    Note: Do not fill the bottle beyond the fill mark. Filling beyond the fill mark will not allow for proper lab mixing.

18. Remove the sampling probe tube from the bottle lid. Save the knurled probe holder and discard the probe tube.

19. Immediately replace the two-hole lid on the sample bottle with the solid lid (no hole). Dispose of the lid with two holes.

20. Wipe any oil off the sample valve.

21. Install the dust cap onto the S·O·S valve and check that the cap is clean on the inside.

For more information refer to Special Instruction, SEBF8482, "Obtaining Oil Sample for Analysis".