DETROIT DIESEL 53
Fuel Injector 2.1.1
attempts, the spray tip cannot be positioned satisfactorily, replace the injector nut.
Test Reconditioned Injector
Before placing a reconditioned injector in service, perform all of the tests (except the visual inspection of the plunger)
previously outlined under Test Injector. The injector is satisfactory if it passes these tests. Failure to pass any one of the
tests indicates that defective or dirty parts have been assembled. In this case, disassemble, clean, inspect, reassemble
and test the injector again.
Before installing an injector in an engine, remove the carbon deposits from the beveled seat of the injector alignment of
the injector and prevent any undue stresses from being exerted against the spray tip.
Use injector tube bevel reamer J 5286-9, Section 2.1.4, to clean the carbon from the injector tube. Exercise care to
remove ONLY the carbon so that the proper clearance between the injector body and the cylinder head is maintained.
Pack the flutes of the reamer with grease to retain the carbon removed from the tube.
Be sure the fuel injector is filled with fuel oil. If necessary, add lean fuel oil at the inlet filter cap until it runs out of the
outlet filter cap.
Install the injector in the engine as follows:
Refer to Fig. 6 and insert the injector into the injector tube with the dowel pin in the injector body registering with
the locating hole in the cylinder head.
Slide the injector rack control lever over so that it registers with the injector rack.
Install the injector clamp, special washer (with curved side toward injector clamp) and bolt. Tighten the bolt to 20-
25 Ib-ft torque. Make sure that the clamp does not interfere with the injector follower spring or the exhaust valve springs.
NOTE: Check the injector control rack for free movement. Excess torque can cause the
control rack to stick or bind.
Move the rocker arm assembly into position and secure the rocker arm brackets to the cylinder head by
tightening the bolts to the torque specified in Section 2.0.
CAUTION: On four valve cylinder heads, there is a possibility of damaging the exhaust valves if the exhaust valve
bridge is not resting on the ends of the exhaust valves when tightening the rocker shaft bracket bolts. Therefore, note the
position of the exhaust valve bridge (Fig. 43) before, during and after tightening the rocker shaft bolts.
Remove the shipping caps. Then install the fuel pipes and connect them to the injector and the fuel connectors.
Use socket J 8932-01 to tighten the connections to 12-15 lb-ft torque.
CAUTION: Do not bend the fuel pipes and do not exceed the specified torque. Excessive
tightening will twist or fracture the flared end of the fuel line and result in leaks. Lubricating
oil diluted by' fuel oil can cause serious damage to the engine bearings.
Perform a complete engine tune-up as outlined in Section 14. However, if only one injector has been removed
and replaced and the other injectors and the governor adjustment have not been disturbed, it will only be necessary to
adjust the valve clearance and time the injector for the one cylinder, and to position the injector rack control lever.
March 1973, SEC 2.1.1