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The following is a list of items that are unique to the Series 60G engine for preventive maintenance (city transit coach): ‪

Coalescing Fuel Filters

Drain coalescing fuel filters daily. Inspect natural gas fuel filter every 6,000 miles (9,600 km). Replace fuel filter if dirt, debris or foreign objects are present inside of the fuel filter. Also, replace if fuel filter seal is damaged. ‪

Note: Oil saturation on the outside of the fuel filter is a NORMAL condition of the oil coalescing process.

Valve Lash

Check valve lash. Valve lash should be inspected and adjusted every 36,000 miles (58,000 km) as specified. ‪

Closed Crankcase Breather System

The closed crankcase breather filter must be replaced every 6000 miles (9,600 km). The filter is located in the remote mounted crank vent assembly. ‪

Dry-Type Air Cleaner

Under no operating condition should the intake restriction exceed 20 inches of water at full load and rated speed. A clogged air cleaner element will cause excessive intake restriction and a reduced air supply to the engine. For equivalent restriction limits for lower speed, refer to Detroit Diesel Corporation Engineering Bulletin No. 39, "Air Cleaner Systems for Detroit Diesel Engines". ‪

Inspect the air cleaner element every 12,000 miles (19,000 km) for coaches. Inspect the air cleaner more often if the engine is operated under severe dust conditions. Replace the element if necessary. Check the gaskets for deterioration and replace, if necessary. If the dry-type air cleaner is equipped with an aspirator, check for aspirator damage or clogging. Clean and repair as necessary. ‪

Engine Lubricating Oil

Change the lubricating oil every 6,000 miles (9,600 km) for city transit coaches. (Refer to Engine Requirements - Lubricating Oil, Fuel and Filters - 7SE272). ‪

Engine Lubricating Oil Filters

Change the lubricating oil filters at each oil change 6,000 miles (9,600 km) for city transit coaches). ‪


Check the coolant level daily before starting the engine. Ensure coolant is up to the proper level. Add coolant as necessary. DO NOT OVERFILL. Check all cooling system lines and hoses for damage, leaks or loose connections. Tighten or replace as necessary. (Refer to Coolant Selections for Detroit Diesel Engines 7SE298). Check for proper inhibitor level at each oil change (15,000 miles or 24,000 km) and add as required; or 6,000 miles (9,600 km) for coaches. ‪

Turbocharger and Wastegate Assembly

Inspect turbocharger mountings, air intake and exhaust ducts, recirculation valve assembly, and wastegate valve assembly, including hoses, for leaks. Check the oil and water inlet and outlet lines and connections for leaks and restrictions to flow. Check for unusual vibrations or noises. If excessive, remove unit from service and have cause corrected. ‪


Check thermostats and seals every 108,000 miles (173,800 km) for coach. Replace the seals and/or thermostat, if necessary. ‪

Spark Plugs

Replace the spark plugs and boot spring assembly every 24,000 miles (38,600 km) for coach; see service manual for plug information, refer to section and refer to section . ‪