Caterpillar 72H PIPELAYER - Maintenance | Annual

Cooling System Coolant Sample (Level 2) - Obtain

• Park the machine on a hard, level surface. Set the engine at low idle speed.

• Open the left side engine compartment. Remove the protective cap from the sampling valve.

• Obtain a sample. For additional information about coolant analysis, see Special Publication, SEBU6250 “Caterpillar Machine Fluids Recommendations” or consult your Caterpillar dealer.

• Replace the protective cap. Close the left side engine compartment.

• Submit the sample for Level 2 analysis.

Final Drive Oil - Change

• Position one final drive so that oil level mark (1) is horizontal. The drain plug (3) will point downward.

• Remove oil filler plug (2).

• Remove drain plug (3). Allow the oil to drain into a suitable container.

• Inspect the drain plug seal. Replace the drain plug seal if the drain plug seal is damaged.

• Clean the drain plug and install the drain plug.

• Fill the final drive with oil to the bottom of the filler plug opening. See Operation and Maintenance Manual, “Capacities Refill”.

• Inspect the condition of the seal of the filler plug. Replace the plug seal if the plug seal is damaged. Wipe the magnet in order to clean the plug. Install the plug.

• Repeat Step 185 to Step 7 in order to change the oil in the other final drive.

Hydraulic System Oil - Change

• Remove hydraulic tank filler cap (1) slowly in order to relieve any pressure.

• Wash the filler strainer and the filler cap in a clean nonflammable solvent.

• Use a 126-7914 Oil Drain Coupling and attach a 1 inch hose. Make sure that enough of the swivel hose bypasses the track assembly and fills into a suitable container.

• Remove oil drain plug (3) which is located under the right fender of the machine.

• Install the swivel hose into the drain plug opening.

• Rotate the swivel hose clockwise in order to open the internal drain valve. Allow the oil to drain into a suitable container.

• Remove the swivel hose. The internal drain valve for the hydraulic tank will close.

• 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).

• Change the hydraulic system filter.

• Install the filler strainer.

• Fill the hydraulic oil tank.

• Inspect the filler cap gasket. Replace the gasket if damage or wear is evident.

• Install the filler cap.

• Start the engine. Operate the engine for a few minutes.

• Maintain the oil level to the “FULL” mark in sight gauge (2). Add oil, if necessary.

• Stop the engine.

Hydraulic System Oil Filter (Pilot) - Replace

• Lower the bulldozer and the ripper to the ground.

• Slowly remove hydraulic tank filler cap (2) in order to relieve the system pressure.

• The pilot filter is located in the compartment in front of the hydraulic tank on the right side of the machine.

• Remove the filter element with a strap type wrench.

• Clean the filter element mounting base. Remove any part of the filter element gasket that remains on the filter element mounting base.

• Install the new pilot filter element by hand.

• Instructions for the installation of the filter are printed on the side of each Caterpillar spin-on filter. For non-Caterpillar filters, refer to the installation instructions that are provided by the supplier of the filter.

• Maintain the hydraulic oil to the “FULL” mark in the sight glass.

• Install hydraulic tank filler cap (2).

• Close access door to the pilot filter.

Track Roller Frame Guides - Inspect

• Raise the front of the machine with the hydraulics of the dozer. Place a 100 mm (4 inch) block under the outside edge of a track grouser. Place the block near the track idler. Lower the machine onto the block.

• Use a grease pencil to make a mark on the tubular section of the front roller frame. Make a mark on the rear of the roller frame. This mark should correspond with the mark that is on the tubular section.

• Raise the front of the machine with the hydraulics of the dozer. Place the block under the inside edge of the same track grouser. Lower the machine onto the block.

• Put a mark on the tubular section of the front roller frame. This mark should correspond with the mark on the rear roller frame. Measure the distance between the two marks on the front roller frame.

• If the distance between the two marks is greater than 4.5 mm (.18 inch), inspect the track roller frame guides for wear.

• Repeat the entire procedure for the other side of the machine.

Refrigerant Dryer - Replace (If Equipped)

• Replace refrigerant dryer if equipped.

• The refrigerant dryer contains the orifice tube and the desiccant that dries the liquid refrigerant.

• Location of the refrigerant dryer is behind the lower access door on the left side of the machine.

• This refrigerant dryer does not have quick couplers.