TM 5-3810-300-24&P-3
EXHAUST VALVE 1.2.2
to compress the valve spring. Remove the two-
piece tapered valve lock (Fig. 4).
8.
Release the tool and remove the spring cap, valve
spring and spring seat; also remove and discard the
valve guide oil seal if used.
To remove an exhaust valve spring with the cylinder
head removed from the engine, use the following
procedure:
1. Support the cylinder head on wood blocks 2" thick
to keep the cam followers clear of the work bench.
2. Remove the fuel pipes from the injector and the
fuel connectors.
3. Remove the two bolts holding the rocker arm shaft
bracket to the cylinder head. Lift the rocker arms
and brackets up and away from the injector.
Fig. 5 - Testing Exhaust Valve Spring
4. Remove the fuel injector.
5. Remove the exhaust valve bridges and bridge
springs, spring seats and caps, as the valve bridge
springs, if used.
spring is no longer required.
6. Remove the exhaust valve spring from the cylinder
head as previously outlined above. In addition, use
Inspect the valve spring seats and caps for wear.
If
a block of wood under the cylinder head to support
worn, replace.
the exhaust valve.
7. Remove the cam followers and push rod
Examine the contact surfaces of the exhaust valve
assemblies as outlined in Section 1.2.1 under
bridge guides, bridges and adjusting screws for wear and
"Remove
Cam
Follower and Push Rod
galling. Replace excessively worn parts.
Assembly (Cylinder Head Removed from Engine)".
Remove Exhaust Valves
Inspect Exhaust Valve Spring
With the cylinder head off the engine, remove the
exhaust valves as follows:
Clean the spring with fuel oil and dry it with compressed
1. Remove the valve springs as outlined under
air. Then inspect the spring for pitted or fractured coils.
"Remove Exhaust Valve Spring" in this section.
Use spring tester J 9666 and any accurate torque
2. Turn the cylinder head over on its side, using care
wrench to check the spring load (Fig. 5).
to keep the valves from dropping out.
3. Number each valve to facilitate re-installation in the
Replace the exhaust valve spring, used on the two-valve
same position. Then, withdraw the valves from the
cylinder head, when a load of less than 25 pounds will
cylinder head.
compress it to 2.20" (installed length).
Inspect Exhaust Valves
The exhaust valve spring used on the current four valve
cylinder head has an outside diameter of approximately
Carbon on the face of a valve indicates blowby due to a
61/64". Replace this spring when a load of less than 25
faulty seat. Black carbon deposits extending from the
pounds will compress it to 1.80" (installed length).
valve seats to the valve guides may result from cold
operation due to light loads or the use of too light a grade
On former four valve cylinder heads a lighter exhaust
of fuel. Rusty brown valve heads with carbon deposits
valve spring (55/64" O.D.) was used for each valve and
forming narrow collars near
also for the valve bridge. Replace this spring when a
load of less than 79 pounds will compress it to a length
of 1.416". When replacement of either the exhaust valve
spring or valve bridge spring is required, it will be
necessary to use the current larger exhaust valve
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