Caterpillar 426 - Monthly Maintenance

Axle Universal Joint (Rear) - Lubricate (All Wheel Steer Machines Only)

• Apply lubricant to the grease fittings for the universal joints of each drive shaft to the final drives. There are two grease fittings for each universal joint.

Cooling System Coolant Additive (DEAC) - Add

• Pull the hood release lever (1) in order to open the engine access door (2) on the top of the machine.

• Slowly loosen the radiator cap in order to relieve system pressure. Remove the radiator cap.

• If necessary, drain enough coolant from the radiator in order to allow the addition of the liquid coolant additive.

• Add 0.24 Liters (.50 pint) of cooling system additive for every 38 Liters (10 US Gallons) of engine cooling capacity.

• Maintain the coolant level within 13 mm (0.5 inch) from the bottom of the filler tube.

• Install the radiator cap. Close the access door.

Differential Oil Level (Front) - Check

• Remove the oil level/fill plug in order to check the oil.

• The oil level should be at the bottom of the plug threads.

• Clean the oil level/fill plug and install the oil level/fill plug.

Differential Oil Level (Rear) - Check

• Remove the oil plug in order to check the oil.

• The oil level should be at the bottom of the plug threads

• Clean the oil plug and install the oil plug

Engine Oil and Filter - Change

• Remove the crankcase drain plug and drain the oil into a suitable container. Clean the crankcase drain plug and replace the crankcase drain plug.

• Remove the engine access panel on the left side of the machine.

• Remove the filter element with a strap type wrench. Refer to Operation and Maintenance Manual, “Oil Filter - Inspect”

• Clean the filter mounting base with a clean cloth. Make sure that the old filter gasket has been removed.

• 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.

• Pull the hood release lever (1) in order to open the engine access door (2) on the top of the machine.

• Remove the oil filler cap (4). Fill the crankcase with new oil. Refer to Operation and Maintenance Manual, “Lubricant Viscosities” and Operation and Maintenance Manual, “Refill Capacities”. Clean the oil filler cap and install the oil filler cap.

• 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. Maintain the oil level in the crosshatched region of the engine oil dipstick (3). Add oil, if necessary.

• Replace the engine access panel and close the engine access door.

Final Drive Oil Level (Front) - Check

• Position the oil fill/drain plug at a horizontal position in order to check the oil level.

• Remove the oil fill/drain plug in order to check the oil level.

• The oil should be level with the bottom of the plug threads.

• Clean the plug and install the plug.

• Repeat the procedure for the other final drive

Final Drive Oil Level (Rear) - Check

• Position the oil fill/drain plug at a horizontal position in order to check the oil level.

• Remove the oil fill/drain plug in order to check the oil level.

• The oil should be level with the bottom of the plug threads.

• Clean the plug and install the plug.

• Repeat the procedure for the other final drive.

Kingpin Bearings (Rear) - Lubricate

• Apply lubricant to the grease fittings for the kingpin bearings of the rear steerable axle. There is a total of four grease fittings.

Sideshift Stabilizer Wear Pads - Inspect

• Check the stabilizers for slop. Shim the stabilizer pads in order to maintain an acceptable fit and reduce slop. Refer to the Service Manual for the correct procedure.

• Note: Do not excessively apply a silicone based lubricant. Dirt can be attracted to the lubricant and dirt can cause abrasion to the pad assemblies and wear to the pad assemblies.

• The stabilizer pads do not normally require any lubrication. If the stabilizers become noisy, a small amount of a silicone based lubricant may be applied.

V-Belts - Inspect/Adjust/Replace

• Empty the bucket. Remove the pin that secures the loader lift arm brace to the left loader lift arm. Raise the loader arm to the maximum height.

• Position the loader lift arm brace over the left lift cylinder rod with the flat end against the cylinder end.

• Push the pin through the holes of the loader lift arm brace and install the cotter pin.

• Slowly lower the loader arms until the loader lift arm brace contacts the top of the lift cylinder and the bosses on the loader arm.

• Stop the engine in order to inspect the belts.

• Remove the engine access panel on the left side of the machine.

• Inspect the condition of the air conditioner belt and the adjustment of the air conditioner belt. The air conditioner belt should deflect 10 mm (0.38 inch) under 110 N (25 lb) of force.

• Loosen the adjusting locknut (1). Loosen the compressor bracket mounting bolt (2).

• Move the compressor until the correct belt tension is reached.

• Tighten the adjusting locknut (1). Tighten the compressor bracket mounting bolt (2).

• Recheck the belt deflection. If the amount of deflection is incorrect, repeat Step 8 to Step 10.

• Install the engine access panel.

• Remove the engine access panel on the right side of the machine.

• Inspect the condition of the alternator belts and the adjustment of the alternator belts. The alternator belts should deflect 10 mm (0.38 inch) under 110 N (25 lb) of force.

V-Belts - Inspect/Adjust/Replace 2

• Loosen the mounting bolt (1). Loosen the adjusting locknut (2).

• Move the alternator until the correct tension is reached.

• Tighten the adjusting locknut (2). Tighten the mounting bolt (1).

• Recheck the belt deflection. If the amount of deflection is incorrect, repeat Step 1 to Step 3.

• Install the engine access panel.

• Start the engine. Raise the loader arms to the maximum height.

• Remove the pin and replace the loader lift arm brace to the stored position on the loader lift arm.

• Lower the bucket to the ground.