Section 2.10
Diesel Fuel Filters (Spin-On)

Two spin-on type filters are used on the Series 60 engine. The first in the fuel flow is a strainer, and the second is a filter. Although they are not marked as such, the threaded sleeves that accept the cartridges are different sizes to prevent mismatching. The primary filter has a 1 in. x 12 thread. The secondary filter has a 13/16 in. x 12 thread. The word "Primary" or "Secondary" is cast onto the top of the respective adaptor. See Figure "Fuel Filters" .‪

Figure 1. Fuel Filters

The spin-on filter cartridges consist of a shell, element, and gasket combined into a unitized replacement assembly. No separate springs or seats are required to support the filters. Effective with 1993 engine production, an optional fuel filter and water separator assembly may be installed in place of the strainer. A fuel shutoff valve or check valve may be installed on the outlet side of the secondary filter.‪

The fuel filter adaptors are attached to the block with two bolts each. Torque these bolts to 58-73 N·m (43-54 lb·ft).‪

The fuel filter system consists of the following:‪

• Spin-on primary fuel filter
• Primary fuel filter adaptor
• Spin-on secondary fuel filter
• Secondary fuel filter adaptor
• Fuel shutoff valve or check valve

Section 2.10.1
Replacement of Fuel Filter

As contaminants build up on the filter medium, a number of factors start to affect vehicle performance:‪

• The fuel delivery rate is reduced, making less fuel available for combustion.
• The fuel pump is forced to work harder to move the same volume of fuel. This subjects internal seals to abnormal conditions which may lead to seal leakage. In extreme cases air can be drawn into the fuel system.
• With the rate of flow slowed, fuel stays in the cylinder head for a longer period of time, allowing its temperature to rise above normal. Because fuel temperature has an affect on engine power, higher fuel temperatures normally result in reduced power.
• If the restriction is severe enough, fuel vaporization can occur, resulting in pockets of air that can further reduce fuel delivery.

All of these conditions can lead to power loss and subsequent operator complaints of "low power" and "reduced vehicle fuel economy" requiring more frequent downshift on grades.‪

To determine if replacement of fuel filter element is necessary. See Figure "Flowchart for Replacement of Fuel Filter Element" .‪

Figure 2. Flowchart for Replacement of Fuel Filter Element

Section 2.10.2
Replacement of Fuel Filter

Replace spin-on primary and secondary fuel filters at the following intervals or earlier, if plugging is indicated:‪

• Truck and Parlor Coach — 24,000 Km (15,000 Miles)
• Transit Coach — 9,600 Km (6,000 Miles)
• Fire Fighting Apparatus — 9,600 Km (6,000 Miles)

Replace the Fuel Pro^® primary filter element when the fuel level in the see-thru filter cover reaches the top of the filter element or after one year of service, whichever comes first. ‪

Replace spin-on secondary filter element at regular 250 hour intervals.‪

A method of determining when filters are plugged to the extent that they should be changed is based on the fuel pressure at the cylinder head fuel inlet fitting and the inlet restriction at the fuel pump. In a clean system, the maximum pump inlet restriction should not exceed 20.3 kPa (6 in. Hg) and must not exceed 41 kPa (12 in. Hg) with a dirty system.‪

At normal operating speeds and with the standard 2.03 mm (0.080 in.) restriction fittings, the fuel pressure at the cylinder head inlet is 345-577 kPa (50-84 psi). Change the fuel filters whenever the inlet restriction at the fuel pump reaches 41 kPa (12 in. Hg) at normal operating speeds and whenever the fuel pressure at the cylinder head inlet fitting falls to the minimum fuel pressure shown above.‪

Spin-on type primary and secondary fuel filters used on Series 60 engines consist of a shell, element, and gasket unitized into the single cartridge and a filter cover, that includes a threaded sleeve to accept the spin-on filter cartridge. An optional fuel and water separator may be installed in place of the standard primary filter.‪

The Fuel Pro Fuel Processor System have primary cartridge-style filter elements installed in see-thru covers mounted on top of the fuel processor bodies. These filter elements must be changed when the fuel level in the see-thru cover reaches the top of the element. The secondary filter element must be replaced every 250 hours or every year, whichever comes first.‪

Fuel Pro^® is a registered trademark of Davco Manufacturing, L.L.C.‪

Replace spin-on type primary or secondary filter elements as follows:‪

1. With the engine shut down, place a suitable container under the filter.
2. A fuel shutoff valve may be installed on the discharge side of the secondary fuel filter. If installed, turn the handle on the shutoff valve to the closed position (perpendicular to the valve).
3. Using a suitable band-type filter wrench, remove the primary and secondary fuel filters. Dispose of the filters in an environmentally responsible manner, according to state and federal (EPA) recommendations.
4. Fill new replacement filters with clean fuel oil, and coat the gaskets lightly with clean fuel oil.

   NOTICE:
   Overtightening may crack or distort the adaptors.‪

5. Thread the new filters onto the adaptors until they make full contact with the gasket and no side movement is evident. Then rotate an additional one-half turn by hand.
6. Turn the handle on the shutoff valve (if installed) to the open position (in line with the valve).

   NOTICE:
   To improve engine starting, have replacement filters filled with fuel and ready to install immediately after used filters are removed. This will prevent possible siphoning and fuel system aeration.‪

   PERSONAL INJURY ‪
   Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.‪ Always start and operate an engine in a well ventilated area. If operating an engine in an enclosed area, vent the exhaust to the outside. Do not modify or tamper with the exhaust system or emission control system.

7. Start the engine, and check for leaks.

   NOTICE:
   Under no circumstances should the starting motor and fuel pump be used to prime the fuel filters. Prolonged use of the starting motor and fuel pump to prime the fuel system can result in damage to the starter, fuel pump, and injectors and cause erratic running of the engine because of air in the lines and filters.‪

   If the engine fails to start after filter replacement, the fuel system will require priming using tool J–5956 . Authorized Detroit Diesel service outlets are properly equipped to perform this service.‪

Replace the fuel and water separator as follows:‪

1. Drain off some fuel by opening the drain valve.
2. Using a strap wrench, remove the element and bowl together. Remove the bowl from the element. The filter and bowl have standard right-hand threads, so turn counterclockwise to remove.
3. Clean the bowl and the O-ring seal.

   NOTICE:
   To avoid damaging the bowl or the filter, do not use tools when tightening.‪

4. Apply a light coating of clean fuel or grease to the O-ring seal, spin the bowl onto the new filter, and tighten by hand .
5. Apply a light coating of clean fuel or grease to the new O-ring seal on the top of the filter. Spin the filter and bowl assembly onto the filter head, and tighten by hand until snug.
6. To eliminate air from the filter, operate the primer pump on the filter head (if equipped) until the fuel purges at the filter assembly.

   PERSONAL INJURY ‪
   Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.‪ Always start and operate an engine in a well ventilated area. If operating an engine in an enclosed area, vent the exhaust to the outside. Do not modify or tamper with the exhaust system or emission control system.

7. Start the engine, and check for leaks. Correct any leaks with the engine off.

Section 2.10.3
Installation of Fuel Filter

Perform the following steps to install the fuel filter:‪

1. Refer to "14.6.13 Fuel Filters (Diesel)" for fuel filter installation.

   Note: There is a fuel system shutoff valve on the discharge side of the secondary fuel filter. This check valve is designed to prevent loss of fuel prime at time of filter replacement.

   PERSONAL INJURY ‪
   To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

   PERSONAL INJURY ‪
   Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.‪ Always start and operate an engine in a well ventilated area. If operating an engine in an enclosed area, vent the exhaust to the outside. Do not modify or tamper with the exhaust system or emission control system.

2. Start and run the engine. Check for leaks.
3. Shut down engine upon completion of test.