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For location of components and systems to be maintained, see Figure 27842 and see Figure 27843 . ‪

1.Weep Hose ‪

9.Coolant Temperature Switch ‪

2.Water Pump ‪

10.Fuel Nozzle ‪

3.Thermostat Housing ‪

11.Crankcase Breather ‪

4.AGR Valve ‪

12.High Pressure Fuel Line ‪

5.Intake Manifold ‪

13.Transfer Pump ‪

6.Water Manifold ‪

14.Coolant Temperature Sensor ‪

7.Rocker Cover ‪

15.Fuel Pump ‪

8.Bleed Line ‪

16.Oil Pan ‪

Preventive Maintenance Service Items (Left Front Engine View)

1.Exhaust Manifold ‪

5.Air Gas Recirculator ‪

2.Rocker Oil Feed Pipe ‪

6.Oil Filter ‪

3.Intake Manifold ‪

7.Turbocharger ‪

4.Water Manifold ‪

8.Starter ‪

Preventive Maintenance Service Items (Right Rear Engine View)

Lubricating Oil

Check the lubricating oil level daily with the engine stopped. If the engine has just been stopped and is warm, wait approximately 20 minutes to allow the lubricating oil to drain back into the oil pan before checking. See Figure 27798 . Add the proper grade of lubricating oil to maintain the correct level on the dipstick. Listed in Table are the recommended engine lubricating oil specifications. ‪

Proper Crankcase Lubricating Oil Level



SAE Viscosity Grade ‪

15W-40 ‪

API Classification ‪

CG-4 ‪

Military Specification ‪

MIL-L-2104E ‪

HT/HS Viscosity ‪

3.7 cP (minimum) ‪

Recommended Engine Lubricating Oil

All diesel engines are designed to use some lubricating oil, so the periodic addition of lubricating oil is normal. See Figure 27797 to determine the degree of lubricating oil usage. ‪

Engine Lubricating Oil Consumption Guidelines


Do not overfill the engine crankcase. Lubricating oil may be blown out through the crankcase breather if the crankcase is overfilled. ‪


If the lubricating oil level is constantly above normal and excess lubricating oil has not been added to the crankcase, consult with an authorized Detroit Diesel service outlet for the cause. Fuel or coolant dilution of lubricating oil can result in serious engine damage. ‪

Change lubricating oil and filter at the intervals listed in Table when using fuel with a sulfur content of less than 0.5 mass percent. ‪

Service Application

Lubricating Oil and Filter Change Interval

Highway Truck and Parcel Truck ‪

6,000 miles or 10,000 kilometers ‪

General Specifications for the Turbotronic 638
Draining of Lubricating Oil with Lube Oil Filter Change

Drain the lubricating oil and remove the lube oil filter as follows: ‪

  1. Position the vehicle or equipment on level ground.
  2. If the engine is cold, run it until it reaches normal operating conditions.
  3. Remove drain plug on the bottom of oil pan. Drain lubricating oil into a suitable container. Always dispose of used lubricating oil in an environmentally responsible manner, according to EPA and state recommendations.

    Note: If the lubricating oil is drained immediately after an engine has been run for some time, most of the sediment will be in suspension and will drain readily.

  4. Remove the spin-on filter cartridge using a strap wrench.
  5. Dispose of the used lubricating oil and filter in an environmentally responsible manner, according to EPA and state recommendations.
  6. Clean the filter adaptor with a clean, lint-free cloth.
Engine Crankcase Refill and Installation of Lube Oil Filter

Select the proper grade of lubricating oil. Listed in Table are the recommended engine lubricating oil specifications. ‪

Refill the engine crankcase and install a new lube oil filter as follows: ‪

  1. Install the drain plug. Torque plug to 12 N m (9 lb ft).
  2. Lightly coat the filter gasket (seal) with clean lubricating oil.
  3. Start the new filter on the adaptor, and tighten by hand until the gasket mates with the mounting adaptor head. Tighten the filter an additional two-thirds turn by hand.
  4. Add new lubricating oil as required to bring the lubricating oil level to the full" mark on the dipstick. The Turbotronic 638 crankcase holds 8.7 L (9 qts).
  5. Start and run the engine.
  6. Stop the engine and wait approximately 20 minutes for the lubricating oil to drain into the oil pan. Add lubricating oil as required to bring the level to the proper mark on the dipstick. See Figure 27798 .

    Proper Crankcase Lubricating Oil Level

  7. Start and run the engine to check for leaks. Repair leaks as required.
Engine Crankcase Refill

Select the proper grade of lubricating oil. Listed in Table are the recommended engine lubricating oil specifications. ‪

Refill the engine crankcase as follows: ‪

  1. Install the drain plug. Torque plug to 12 N m (9 lb ft).
  2. Add new lubricating oil as required to bring the lubricating oil level to the full" mark on the dipstick. The Turbotronic 638 crankcase holds 8.7 L (9 qts).
  3. Start and run the engine.
  4. Stop the engine and wait approximately 20 minutes for the lubricating oil to drain into the oil pan. Add lubricating oil as required to bring the level to the proper mark on the dipstick. See Figure 27798 .

    Proper Crankcase Lubricating Oil Level

  5. Start and run the engine to check for leaks. Repair leaks as required.

Lubricating Oil Filter

Install a new spin-on oil filter at a maximum of 6,000 miles (10,000 km) on vehicle engines or every 6 months, whichever comes first. Install a new oil filter, turning it until they contact the gasket fully with no side movement. Turn the full-flow filter an additional 2/3 turn by hand. See Figure 27918 . ‪

1.Oil Filter Element ‪

Lubricating Oil Filter Location

Make a visual inspection of all lubricating oil lines for wear and/or chafing. If any indication of wear is evident, replace the oil lines and correct the cause. ‪

Check for oil leaks after starting the engine. ‪

Fuel and Fuel Tank

Keep the fuel tank filled to reduce the condensation to a minimum. Select the proper grade of fuel in accordance with the Fuel Specifications. Refer to section . ‪

At the end of each day, refill the fuel tank to prevent condensation from contaminating the fuel. Condensation formed in a partially filled tank promotes the growth of microorganisms that can clog fuel filters and restrict fuel flow. To prevent microbe growth add a biocide to the fuel tank or primary fuel supply. Follow manufacturer's usage, handling, and safety recommendations. ‪

Water accumulation can be controlled by mixing isopropyl alcohol (dry gas) into the fuel oil at a ratio of one pint (0.5 L) per gallon (125 L) fuel (or 0.10% by volume). ‪

Open the drain at the bottom of the fuel tank every 12,000 miles/19,000 km (300 hours for industrial applications), to drain off any water and sediment. ‪

Every 12 months or 60,000 miles/97,000 km (600 hours for industrial applications), whichever comes first, tighten all fuel tank mountings and brackets. (Refer to OEM maintenance guidelines.) At the same time, check the seal in the fuel tank cap, the breather hole in the cap and the condition of the flexible fuel lines. Repair or replace the parts as necessary. (Refer to OEM maintenance guidelines.) ‪

Units in storage are particularly susceptible to microbe growth. The microbes live in the fuel-water interface. They need both liquids to survive. These microbes find excellent growth conditions in the dark, quiet, non-turbulent nature of the fuel tank. ‪

Microbe growth can be eliminated through the use of commercially available biocides. There are two basic types on the market: ‪

  • The water soluble type treats only the tank where it is introduced. Microbe growth can start again if fuel is transferred from a treated to an untreated tank.
  • The diesel fuel soluble type, such as ``Biobor" manufactured by U.S. Borax (or equivalent), treats the fuel itself, and therefore, the entire fuel system.

Fuel Lines and Flexible Hoses

Make a visual check for fuel leaks at all engine-mounted fuel lines and connections, and at the fuel tank suction and return lines. Since fuel tanks are susceptible to road hazards, leaks in this area may best be detected by checking for accumulation of fuel under the tanks. ‪

The performance of engine and auxiliary equipment is greatly dependent on the ability of flexible hoses to transfer lubricating oil, air, coolant and fuel oil. Diligent maintenance of hoses is an important step in ensuring efficient, economical and safe operation of the engine and related equipment. ‪

Check hoses daily as part of the pre-start up inspection. Examine hoses for leaks and check all fittings, clamps and ties carefully. Be sure that hoses are not resting on or touching shafts, couplings, heated surfaces, including exhaust manifolds, any sharp edges or other obviously hazardous areas. Since all machinery vibrates and moves to a certain extent, clamps and ties can fatigue with age. To ensure continued proper support, inspect fasteners frequently and tighten or replace them, as necessary. (Refer to OEM maintenance guidelines.) ‪

Investigate leaks immediately to determine if hoses have ruptured or worn through. Take corrective action immediately. Leaks are not only potentially detrimental to machine operation, but they also result in added expense caused by the need to replace lost fluids. ‪

Personal injury and/or property damage may result from fire due to the leakage of flammable fluids such as fuel or lube oil. ‪

A hose has a finite service life. The service life of a hose is determined by the temperature and pressure of the air or fluid within it, its time in service, its mounting, the ambient temperatures and amount of flexing and vibration to which it is subjected. With this in mind, all hoses should be thoroughly inspected annually. Look for cover damage or indications of damaged, twisted, worn, crimped, brittle, cracked or leaking lines. Hoses having the outer cover worn through or damaged metal reinforcement should be considered unfit for further service. ‪

All hoses in or out of machinery should be replaced during major overhaul or after a maximum of five years service. ‪

Cooling System

Check the coolant level daily. Be sure coolant is full to the bottom of the radiator filler neck and is visible in the reservoir when cold. Add coolant, as necessary. ‪

Note: Do not overfill the coolant system.

Make a visual check for cooling system leaks. Check for an accumulation of coolant beneath the vehicle during periods when the engine is running and when the engine is stopped. ‪

Note: In order to ensure the integrity of the cooling system, it is recommended that a periodic cooling system pressure check be performed. Pressurize the cooling system 103-138 kPa (15-20 lb/in. 2 ) using radiator cap and cooling system tester, J 24460-01. Do not exceed 138 kPa (20 lb/in. 2 ). Any measurable drop in pressure may indicate an external/internal leak. Whenever the oil pan is removed, the cooling system should be pressure checked as a means of identifying any internal coolant system leaks.

Clean the cooling system every 24 months using a good radiator cleaning combination in accordance with the instructions on the container. After the cleaning operation, rinse the cooling system thoroughly with fresh water. Then fill the system with the proper antifreeze/water mixture and pre-charge of inhibitors. ‪

Inspect all of the cooling system hoses at least once every 30,000 miles/48,000 km (300 hours for industrial applications) to be sure the clamps are tight and properly seated on the hoses and to check for signs of deterioration. Replace the hoses, if necessary. Refer to OEM maintenance guidelines. ‪

Drain the engine coolant as follows: ‪

  1. Allow engine to cool.

    Do not remove the pressure control cap from the radiator or attempt to drain the coolant until the engine has cooled. Once the engine has cooled, use extreme caution when removing the cap. The sudden release of pressure from a heated cooling system can result in a loss of coolant and possible personal injury (scalding, eye injury, etc.) from the hot liquid. ‪

  2. Remove radiator pressure cap.
  3. Open valve at bottom of radiator.
  4. Collect used antifreeze in a suitable container, and dispose of the solution in an environmentally responsible manner, according to state and federal (EPA) recommendations.
  5. Close any drain valves.
  6. Refill the system with proper antifreeze and clean soft water mixture.
  7. Purge entrapped air by allowing the engine to warm-up without the pressure cap installed. With the transmission in neutral, increase engine speed above 1000 r/min. Add coolant as required.
  8. Allow engine to cool.
  9. Install the pressure cap after filling the coolant level to the bottom of the radiator filler neck.

If the cooling system is contaminated, flush the cooling system as follows: ‪

  1. Drain the coolant from the engine.
  2. Refill with soft clean water.

    Note: If the engine is hot, fill slowly to prevent rapid cooling and distortion of the engine castings.

  3. Start the engine and operate it for 15 minutes after the thermostats have opened to thoroughly circulate the water.
  4. Drain the unit completely.
  5. Refill with clean water and operate for 15 minutes after the thermostats have opened.
  6. Drain the unit completely.
  7. Fill with 50/50 antifreeze/water and precharge of inhibitor.
  8. Purge entrapped air by allowing the engine to warm-up without the pressure cap installed. With the transmission in neutral, increase engine speed above 1000 r/min. Add coolant as required.
  9. Allow engine to cool.
  10. Install the pressure cap after filling the coolant level to the bottom of the radiator filler neck.

Drive Belts

New standard vee-belts and Powerband belts will stretch after the first few hours of operation. Run the engine for 10 to 15 minutes at 1200 r/min to seat the belts, then readjust the tension. Check the belts and tighten the fan drive, battery charging generator or alternator and other accessory drive belts after 1/2 hour or 15 miles and again after 8 hours or 250 miles (400 km) of operation. Thereafter, check the tension of the drive belts every 100 hours or 12,000 miles (19,000 km) and adjust, if necessary. Belts should be neither too tight nor too loose. Belts that are too tight impose excess loads on the crankshaft, fan and/or alternator bearings, shortening both belt and bearing life. Excessively overtightened belts can result in crankshaft breakage. A loose belt will slip and may cause damage to accessory components. ‪

With a belt tension gage, J 23600, or equivalent, adjust the belt tension. The belt deflection under 7-8 N (15-18 lb) of force will not exceed 2.54 cm (1 in.) of travel. ‪

Inspect for Belt Wear

Accelerated wear on any part of the belt fabric backing, tensile cord, or rubber is a concern and should be investigated. The causes of accelerated wear are: ‪

  • Drive misalignment
  • Incorrect belt length
  • Environmental conditions - temperature, excessive exposure to engine fluids, etc.
  • Abrasive material - stones, sand, metal shavings, etc.


Visually inspect the mountings, intake and exhaust ducting and connections for leaks daily. Check the oil inlet and outlet lines for leaks or restrictions to oil flow. Check for unusual noise or vibration and, if excessive, stop the engine and do not operate until the cause is determined. ‪

To avoid personal injury or turbocharger damage, do not remove, attach, or tighten turbocharger air intake ducting while the engine is operating or operate the engine with the ducting removed. ‪

Periodically inspect the air-to-air charge cooler for dirt, mud, etc. buildup and wash off. Check the cooler, ductwork, and flexible connections for leaks and have repaired or replaced, as required. ‪

Check heat-insulating exhaust system blankets (if used) for damage daily. Torn, matted, crushed, oil-soaked, or otherwise damaged insulation blankets must be replaced immediately. ‪


Check the hydrometer eye" of maintenance-free batteries for charge. See Figure 27799 . If lead-acid or low maintenance batteries are used, check the specific gravity of each cell every 150 hours. Check more frequently in warm weather due to the more rapid loss of water through evaporation. ‪

Maintenance-Free Battery Eye" Location

To avoid possible personal injury and/or engine damage from accidental engine startup, always disconnect the battery before servicing the electrical system. To avoid alternator damage when removing battery connections, disconnect the negative (-) terminal first. Reconnect the negative terminal last. ‪

Maintain the electrolyte level according to the battery manufacturer's recommendations, but do not overfill. Overfilling can cause poor performance or early failure. ‪

3Keep the terminal side of the battery clean. When necessary, wash with a solution of baking soda and water. Rinse with fresh water. Do not allow the soda solution to enter the cells. ‪

Inspect the cables, clamps, and hold-down brackets regularly. Clean and reapply a light coating of petroleum jelly when needed. Have corroded or damaged parts replaced. ‪

If the engine is to be out of service for more than 30 days, remove the batteries and store in a cool, dry place. Keep batteries fully charged, if possible. Replace any battery that fails to hold a charge. ‪

Periodically check battery connections for corrosion and tightness. If necessary, remove connections and wire brush any corrosion from terminals and cable ends. Replace damaged wiring. ‪

Air Cleaner

The air cleaner element should be inspected every 30,000 miles (48,000 km) or 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. ‪

Under no engine operating conditions should the air inlet restriction exceed 20 inches of water (5.0 kPa). A clogged air cleaner element will cause excessive intake restriction and a reduced air supply to the engine. This, in turn, can result in increased fuel consumption, inefficient engine operation and reduced engine life. ‪

Note: Dry-type air cleaner elements should be replaced after one year of service or when the maximum allowable air intake restriction has been reached, whichever comes first.

Inspect the entire air system for leaks daily. Look especially for torn air inlet piping or boots and loose or damaged clamps. Have worn or damaged parts repaired or replaced, as required. Retighten any loose connections. ‪

Fuel Filters

Install a new spin-on fuel filter element on vehicle engines every 12,000 miles (19,000 km) or every twelve months, whichever comes first. Replace spin-on elements immediately if plugging is indicated, regardless of mileage or hour intervals. ‪

Water Pump and Coolant Inhibitor

Visually inspect the water pump for leaks between the water pump casting and cylinder block. If leaks are visible, replace the water pump gasket. ‪

The water pump weep hose" should be inspected every 6 months to ensure no coolant leakage. See Figure 27919 . ‪

1.Weep Hose ‪

Weep Hose Location

Test the coolant system antifreeze for correct nitrite and glycol concentrations. ‪

Detroit Diesel recommends a coolant solution mixture of 50% fresh water and 50% antifreeze with rust and corrosion inhibitor or similar liquid. ‪

Cranking Motor

For information, contact the Detroit Diesel Technical Service Group. ‪

Air System

All the connections in the air system should be checked to make sure they are tight. Check all hoses and ducting for punctures, deterioration or other damage and replace, if necessary. ‪

Exhaust System

Have the exhaust manifold retaining bolts and other connections checked for tightness. ‪

Visually check the muffler, cross-over pipe, and tailpipe for rust, dents, holes, or cracks. Replace damaged components as necessary. ‪

Engine (Steam Clean)

Steam clean the engine and engine compartment every 60,000 miles (97,000 km) or 2,000 hours, whichever comes first. ‪


Do not apply steam or solvent directly on the battery-charging alternator, starting motor, electronic components, sensors, or other electrical components, as damage to electrical equipment may result. ‪


It may be necessary to clean the radiator more frequently if the engine is being operated in extremely dusty or dirty areas. ‪

To avoid personal injury when blow drying, wear adequate eye protection (safety glasses or face plate) and do not exceed 276 kPa (40 lb/in. 2 ) air pressure. ‪

The exterior of the radiator core should be inspected every 12 months or 30,000 miles (48,000 km) and, if necessary, cleaned with a quality grease solvent, such as mineral spirits, and dried with compressed air. ‪

Note: Fuel oil, kerosene or gasoline should not be used.

Oil Pressure

Under normal operation, oil pressure is noted each time the engine is started. In the event the equipment is equipped with warning lights rather than pressure indicators, the pressure should be checked and recorded every 60,000 miles (97,000 km). ‪

Battery-Charging Alternator

Terminals should be checked for corrosion and loose connections and wiring inspected for damaged or frayed insulation. Have wiring repaired or replaced, as required. ‪

Precautions must be taken when working on or around the alternator. The diodes and transistors in the alternator circuit are very sensitive and can be easily destroyed. ‪

  1. Avoid grounding the output terminal. Grounding an output wire or terminal of an alternator (which is always hot, regardless of whether or not the engine is running) and accidentally reversing the battery polarity will result in equipment damage.

    Reversing battery polarity can also result in personal injury caused by the sudden discharge of electrolyte from the battery vents and/or the sudden rupture of the battery case caused by explosion of internal hydrogen gas. ‪

  2. Do not reverse battery connections. This can cause battery damage.
  3. Never disconnect the battery while the alternator is operating. Disconnecting the battery can result in damage to the alternator diodes. In applications which have two sets of batteries, switching from one set to the other while the engine is running will momentarily disconnect the batteries. This can result in equipment damage.
  4. If a booster battery is to be used, batteries must be connected correctly (negative to negative, positive to positive) to avoid equipment damage.
  5. Never use a fast charger with the batteries connected or as a booster for battery output.

Engine and Transmission Mounts

The engine and transmission mounting bolts and the condition of the mounting pads should be checked every 24,000 miles (39,000 km) and tightened and/or repaired as necessary. ‪

Compression Test

The compression should be checked and recorded every 60,000 miles (97,000 km). ‪

Loss of compression causes loss of power, greater fuel consumption, smoke at the exhaust, low acceleration, unsteady slow idle, difficulty in starting, and bearing seizure because of engine overheating. ‪

Pressure test the engine as follows: ‪

  1. Remove the fuel nozzles from the cylinder head to be tested. Refer to section .
  2. Clean the fuel nozzle bore and attach special tool adaptor, VM 1021 and a pressure gage.
  3. Set the pressure gage to zero reading. Crank the engine over with the starter (300 r/min).

    Engine Speed (r/min)

    Compression Values kPa (lb/in. 2 )

    300 (r/min) ‪

    2353-2549 (341-370) ‪

    750 (r/min) ‪

    3530-3727 (512-540) ‪

    1500 (r/min) ‪

    4119-4315 (597-626) ‪

    Turbotronic 638 Compression Values
  4. Measure the compression and compare with the values listed in Table .
    1. If the values are lower than indicated or with a difference in readings between cylinders that is greater than 490 kPa (72 lb/in. 2 ), check for faulty rings, valves, cylinders, and pistons.
    2. If the values are within specification (listed in Table ), reuse the engine.

Thermostat and Seal

Replace the thermostat and seal every 48,000 miles (77,000 km) on vehicle engines. ‪

Crankcase Breather

Inspect the crankcase breather every 48, 000 miles (77,000 km) on vehicle engines. ‪

Cooling System Hoses

Inspect the cooling system hoses for cracking, kinking, and blistering. ‪