Caterpillar 257 - Annual Maintenance

Engine Oil and Filter - Change

• Open the engine access door. Refer to Operation and Maintenance Manual, “Access Doors and Covers”.

• Tilt the radiator upward. Refer to Operation and Maintenance Manual, “Radiator Tilting”.

• Pull the drain hose for the crankcase (3) through the opening in the rear of the machine (4) and remove the plug in the end of the drain hose.

• Open the crankcase drain valve (1) and drain the oil into a suitable container. Close the crankcase drain valve. Install the plug in the drain hose.

• Remove the filter element (2) with a strap type wrench. Refer to Operation and Maintenance Manual, “Oil Filter - Inspect” in order to inspect the used filter for debris.

• Apply a thin film of clean engine oil to the sealing surface of the new filter element.

• Install the new filter element by hand. When the gasket contacts the filter base, tighten the filter for an additional 3/4 turn.

• Remove the oil filler plug (6). Fill the crankcase with new oil. See Operation and Maintenance Manual, “Lubricant Viscosities” and Operation and Maintenance Manual, “Refill Capacities”. Clean the oil filler plug and install the oil filler plug.

• Start the engine and allow the oil to warm. Check for leaks.

• Stop the engine and allow the oil to drain back into the oil pan. Fill the crankcase to the “FULL” mark on the dipstick (5). Do not exceed the “FULL” mark on the dipstick. Add oil or drain oil if it is necessary.

• Tilt the radiator downward.

• Close the engine access door.

Bogie and Idler Oil Level - Check

• Inspect the seals on the tubes for the bogies and the idlers during the walk around inspection. If a seal is leaking, replace the seal.

• The 267B (S/N: CYC 954-UP), 277B (S/N: MDH 3315-UP), and 287B (S/N: ZSA 2205-UP) have sealed bearings. The bogie is maintenance free. If maintenance is required on the bogie, please refer to your Caterpillar dealer.

Hydraulic System Oil - Change

• Remove the hydraulic tank filler cap.

• Remove the access panel in the belly guard underneath the machine.

• Remove the plug from the end of the drain hose. Pull the drain hose through the access panel in the belly guard. Open the drain valve and drain the oil into a suitable container.

• Close the drain valve and pull the drain hose back into the machine. Install the drain plug into the drain hose.

• Change the hydraulic system filter. Refer to Operation and Maintenance Manual, “Hydraulic System Oil Filter - Change”.

• Fill the hydraulic system oil tank. Refer to Operation and Maintenance Manual, “Lubricant Viscosities” and Operation and Maintenance Manual, “Capacities (Refill)”.

• Maintain the hydraulic oil level approximately in the middle of the sight gauge.

• Check the oil level with the loader arms in the fully lowered position.

• Install the hydraulic tank filler cap.

Sprocket - Inspect

• In order to service the drive sprocket, the tracks must be removed. Refer to Operation and Maintenance Manual, “Track (Rubber) - Remove/Install”.

• The drive sprocket is equipped with two types of sleeves. The inner sleeves (2) are held in position by the rings of the sprocket (4) and (5). The outer sleeves (3) are free to rotate on the inner sleeves.

• Measure thickness (A) for the outer sleeves. If the thickness of the outer sleeves measures less than the minimum thickness that is listed in the following table replace the sleeves.

• The inner rings (5) and the outer rings (4) of the drive sprocket will wear from the rotation of the outer sleeves. Measure the thickness (B) of the inner rings and outer rings. If the thickness of the inner ring or outer ring measures less than the minimum thickness that is listed in the following table replace the ring.

Sprocket Bearings - Lubricate

• Use a mallet in order to pound the housing plug inward until the plug falls out of the housing. If the plug was damaged during removal, replace the plug.

• Wipe the old grease out of the housing.

• Pull out the bearing seal. Replace the seal if the seal is damaged.

• Pack the bearing with clean grease and push the seal into position. Place clean grease on the outside of the seal in order to protect the seal.

• If the old housing plug is reinstalled, reverse the housing plug and pound the plug into the housing.

Fuel Injection Timing - Check

• A qualified mechanic should adjust the fuel injection timing because special tools and training are required.

• Refer to the Service Manual for the complete adjustment procedure for the fuel injection timing. Refer to your Caterpillar dealer for the complete adjustment procedure for the fuel injection timing.