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 dirt or other foreign matter from entering
the injector.
4.
Remove the two bolts holding the rocker arm shaft brackets to the cylinder head and remove the brackets and shaft.
5. Remove the cylinder block air box cover so that the piston travel may be observed, then turn the crankshaft until the
piston is at the top of its stroke.
6. Thread the spring compressor tool into one of the rocker arm support bolt holes (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 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.
3.
Remove the two bolts holding the rocker arm shaft
Fig. 3 - Testing Valve Spring
Fig. 4 - Cleaning Valve Guide
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