651E Wheel Tractor-Scraper Hydraulic System Oil - Change Caterpillar

Hydraulic System Oil - Change
651E Wheel Tractor-Scraper [SEBU6963]
651E Wheel Tractor-Scraper Hydraulic System Oil - Change


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, "AVSpare Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on AVSpare products.

Dispose of all fluids according to local regulations and mandates.

Note: If the hydraulic oil is not being monitored by the AVSpare S·O·S Oil Analysis program, change the hydraulic oil at every 2000 service hour interval.

The machine must meet the following conditions before you change the hydraulic tank oil.

  • 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.

Wipe all surfaces around openings before adding oil.

  1. Move the hydraulic controls in order to relieve the system pressure.

    Illustration 1g00102868

  1. Remove the oil filler cap for the hydraulic system slowly in order to relieve pressure. Also remove the oil filler strainer.

  1. Wash the filler screen and the filler cap in a clean nonflammable solvent.

    Illustration 2g00102872

  1. Remove the drain plug (1). The drain plug is located in the bottom of the hydraulic tank.

  1. Open the tank drain valve (2). Allow the oil to drain into a suitable container. Close the tank drain valve.

    Note: Discard the drained fluids according to local regulations.

  1. Change the hydraulic system filters. See Operation and Maintenance Manual, "Hydraulic System Oil Filter - Replace".

  1. Clean the drain plug and install the drain plug. Tighten the drain plug to a torque of 68 ± 7 N·m (50 ± 5 lb ft).

  1. Install the filler screen.

  1. Fill the hydraulic tank. See Operation and Maintenance Manual, "Capacities (Refill)".

  1. Inspect the gasket for the oil filler cap. If the gasket is damaged, replace the gasket.

  1. Install the oil filler cap.

  1. Start the engine and run the engine for a few minutes.

    Illustration 3g00102874

  1. Maintain the oil level above the "ADD" mark in the sight gauge. 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.

  1. Stop the engine. If necessary, tighten any loose clamps and any loose connections. Replace any damaged hoses.

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