TM 5-3895-346-14
EXHAUST VALVES
ENGINE OVERHAUL
Sticking valves may eventually become bent or broken by being held in the open position and struck by the
piston.
It is highly important that injector timing and valve clearance be accurately adjusted and checked periodically.
Improperly timed injectors or tightly adjusted valves will have adverse effects upon combustion.
Remove Exhaust Valve Spring (Cylinder Head Installed)
An exhaust valve spring may be removed, without removing the cylinder head from the engine, as follows:
1. Clean and remove the valve rocker cover.
2. Crank the engine over to bring the valve and injector rocker arms in line horizontally.
CAUTION
When using a wrench on the crankshaft bolt at the front of the engine, do not turn
the crankshaft in a left-hand direction of rotation as this could loosen the bolt.
3. Disconnect and remove the fuel pipes from the injector and the fuel connectors.
CAUTION
Immediately after removing the fuel pipes, cover each injector opening with a
shipping cap to prevent dirt or other foreign matter from entering the injector.
4. Remove the two bolts holding the rocker arm shaft brackets to the cylinder head. Then remove the
brackets and shaft.
5. Remove the cylinder block air box cover so that piston travel may be observed, then turn the crankshaft
until the piston is at the top of its stroke.
6. Thread the valve spring compressor adapter tool J 7455-4 into one of the rocker arm bracket boltholes in
the cylinder head (Fig. 2). Then compress the spring and remove the two-piece valve lock.
7. Release the tool and remove the valve spring cap, valve spring, and spring seat.
Remove Exhaust Valves and Valve Springs (Cylinder Read Removed)
With the cylinder head removed from the engine, remove the exhaust valves and springs as follows:
1. Support the cylinder head on 2-inch thick woodblocks to keep the cam followers clear of the bench.
2. Remove the fuel pipes from the injectors and the fuel connectors.
CAUTION
Immediately after removing the fuel pipes, cover each injector opening with a
shipping cap to prevent dirt or other foreign matter from entering the injector.
Figure 2. Removing Valve Spring Using Tool J 7455
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