1.2.2
Exhaust Valves
DETROIT DIESEL 53
The cylinder head must first be removed before the
exhaust valves, valve seat inserts or valve guides can
be removed for replacement or reconditioning.
However, the valve springs may be replaced without
removing the cylinder head.
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.
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
Fig. 4. - Cleaning Valve Guide
dirt or other foreign matter from entering
the injector.
piston travel may be observed, then turn the crankshaft
until the piston is at the top of its stroke.
4. Remove the two bolts holding the rocker arm shaft
6. Thread the spring compressor tool into one of the
brackets to the cylinder head and remove the brackets
rocker arm support bolt holes (Fig. 2). Then compress
and shaft.
the spring and remove the two-piece valve lock.
7. Release the tool and remove the valve spring cap,
5. Remove the cylinder block air box cover so that the
valve spring and spring seat.
Remove Exhaust Valves and Valve Springs
(Cylinder Head Removed)
With the cylinder head removed from the engine,
remove the exhaust valves and springs as follows:
1. Support the cylinder head on 2" thick wood blocks to
keep the cam followers clear of the bench.
2. Disconnect and 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.
Fig. 3. - Testing Valve Spring
3. Remove the two bolts holding the rocker arm shaft
1972 General Motors Corp.
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