Engine Systems
DETROIT DIESEL
Remove Injector
An injector may be removed in the following manner:
1.
Clean and remove the valve rocker cover.
2. Disconnect the fuel pipes from both the injector and the fuel
connectors.
3. Immediately after removing the fuel pipes, cover the injector inlet and
outlet fittings with shipping caps to prevent dirt from entering.
4. Turn the crankshaft manually in the direction of engine rotation or
crank the engine with the starting motor, if necessary, until the rocker arms
for the particular cylinder are aligned in a horizontal plane.
CAUTION: If a wrench is used on the
crankshaft bolt at the front of the engine, do
not turn the crankshaft in a left- hand
direction of rotation as the bolt will be
loosened. Remove the starting motor and
use a pry bar against the teeth of the
flywheel ring gear to turn the crankshaft.
5. Remove the two rocker shaft bracket bolts and swing the rocker arm
Fig. 3. Removing Injector from Cylinder Head
assembly away from the injector and valves.
6.
Remove the injector clamp bolt, washer and clamp.
7.
Loosen the inner and outer adjusting screws on the injector rack control lever and slide the lever away from the injector.
8.
Free the injector from its seat as shown in Fig. 3 and lift it from the cylinder head.
9.
Cover the injector hole in the cylinder head to keep foreign particles out of the cylinder.
Install Injector
Before installing an injector, be sure the beveled seat of the injector tube is free from dirt particles and carbon deposits.
A new or reconditioned injector may be installed by reversing the sequence of operations given above for removal.
Be sure the injector is filled with fuel oil. If necessary, add clean fuel oil at the inlet filter until it runs out the outlet filter.
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 before, during and after
tightening the rocker shaft bracket bolts.
Do not tighten the injector clamp bolt to more than 20-25 lb-ft (27-34 Nm) torque, as this may cause the moving parts of the injector to
bind. Tighten the rocker shaft bolts to 50-55 lb-ft (68-75 Nm) torque.
Align the fuel pipes and connect them to the injector and the fuel connectors. Use socket J 8932-01 and a torque wrench to tighten the
fuel pipe nuts to 12-15 lb- ft (16-20 Nm) torque.
CAUTION: Do not bend the fuel pipes and do not exceed the specified torque. Excessive tightening
will twist or fracture the flared ends of the fuel pipes and result in leaks. Lubricating oil diluted by fuel oil
can cause serious damage to the engine bearings.
Time the injector, position the injector rack control lever and adjust the exhaust valve clearance (cold setting) as outlined in the engine
tune-up procedure. If all of the injectors have been replaced, perform a complete tune-up on the engine.
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