657G Wheel Tractor-Scraper Caterpillar

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

Note: The normal hydraulic oil change interval is at every 2000 Service Hours or 1 Year. By performing S·O·S oil analysis, the hydraulic oil change interval may be extended to 4000 Service Hours or 2 Years. S·O·S oil analysis must be performed at every 500 Service Hours or 3 Months in order to extend the hydraulic oil change interval. The results from the S·O·S oil analysis will determine if the hydraulic oil change interval may be extended. If S·O·S oil analysis is not available, the hydraulic oil change interval must remain at every 2000 Service Hours or 1 Year . Refer to the Operation and Maintenance Manual, "S·O·S Information".

Note: Cat HYDO Advanced 10 has a 50% increase in the standard oil drain interval for machine hydraulic systems (3000 hours versus 2000 hours) over second and third choice oils - when following the maintenance interval schedule for oil filter changes and for oil sampling that is stated in the Operation and Maintenance Manual for your particular machine. 6000 hour oil drain intervals are possible when using S·O·S Services oil analysis. Contact your Cat dealer for details.

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Hydraulic tank drain valve (4) is located on the bottom of the hydraulic tank at the right rear of the tractor.

Note: Before you change the hydraulic tank oil, the machine must meet the following conditions:

• The machine must be level.

• The parking brake must be applied.

• The hydraulic oil must be warm.

• The transmission control must be in NEUTRAL.

• The bowl must be lowered.

Hydraulic oil filler cap (2) is located on top of the hydraulic tank.

1. Clean the hydraulic oil filler cap.

2. The hydraulic oil filler cap is a locking cap. If a padlock is on the cap, remove the padlock. Raise lever (1) in order to engage the lug.

3. Turn the hydraulic oil filler cap counterclockwise in order to remove the cap. Slowly remove the cap in order to relieve pressure in the hydraulic tank.

4. Remove hydraulic tank drain plug (5).

5. Open hydraulic tank drain valve (4). Allow the oil to drain into a suitable container.

6. Change the hydraulic system filters. Refer to the following topics that apply to your machine:

   • Operation and Maintenance Manual, "Auger Hydraulic System Oil Filter - Replace"

   • Operation and Maintenance Manual, "Hydraulic System Oil Filter (Pilot) - Replace"

   • Operation and Maintenance Manual, "Hydraulic System Oil Filter - Replace"

7. Close the hydraulic tank drain valve.

8. Clean the hydraulic tank drain plug. Install the drain plug.

9. A screen is located under hydraulic oil filler cap (2). Remove the screen.

10. Wash the screen in clean, nonflammable solvent. Inspect the screen for damage. If the screen is damaged, replace the screen.

11. Install the screen.

12. Fill the hydraulic tank to the proper level. Refer to the following topics:

    • Operation and Maintenance Manual, "Lubricant Viscosities"

    • Operation and Maintenance Manual, "Capacities (Refill)"

13. Inspect the cap seal for damage. If the seal is damaged, replace the seal.

14. Install the hydraulic oil filler cap.

15. Start the machine. Run the machine at a low idle.

16. Check the hydraulic oil level. The oil level must be within the green range of sight gauge (3). Add oil, if necessary.

    Note: The oil must be free from bubbles. If there are bubbles in the oil, then air is entering the hydraulic system. Inspect the suction hoses and the clamps. If necessary, tighten any loose clamps and any loose connections. Replace any damaged hoses.

17. Stop the engine.