The following is a list of items that are unique to the Series 50G engine for preventive maintenance (city transit coach):
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.
Check valve lash. Valve lash should be inspected and adjusted every 60,000 miles as specified.
The closed crankcase breather filter must be replaced every 6000 miles. The filter is located in the remote mounted crankvent assembly.
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 (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.
Change the lubricating oil every 6,000 miles for city transit coaches. (Refer to Engine Requirements - Lubricating Oil, Fuel and Filters - 7SE272).
Change the lubricating oil filters at each oil change 6,000 miles for city transit coaches).
Check the coolant level daily before starting the engine. Make sure 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) and add as required or 6,000 miles (coaches).
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.
Every 18,000 miles, vacuum check the turbocharger compressor recirculation valve for leakage per the service manual. If the valve assembly does not hold the vacuum specified, the valve needs to be disassembled and inspected for defective components.
Check thermostats and seals every 108,000 miles (coach), whichever comes first. Replace the seals and/or thermostat, if necessary.
Inspect spark plug wires at spark plug change interval for cracks and/or deterioration, and for proper routing. Replace wires at 108,000 miles (coach).