Detroit Diesel 4000 Series, Service Manual, Page: 623 / 2706

SERIES 4000 12/16V SERVICE MANUAL
23. Ensure that mating surface for valve gear housing is seated correctly.
24. From the combustion side, press valve guide out of cylinder head with removal brass drift.
NOTE:
Remove cap plug only if necessary (e.g., in event of leakage).
25. To remove cap plug, use brass drift to carefully knock the edge of one side of the cap plug
(1) inwards until it tilts in the bore. See Figure 358.
1. Cap Plug
Figure 358 Removing Cap Plug
26. Withdraw cover with pliers.
27. When removing, take care that cover does not fall into bore and that sealing surface
of bore is not damaged.
NOTICE:
Never drill cap plug, as metal chips in coolant jacket of cylinder
head can cause localized overheating.
All information subject to change without notice.
Copyright © DETROIT DIESEL CORPORATION
C -477