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Page 200
REPAIR INSTRUCTIONS
3. Install cup plugs in the cylinder head, using
the appropriate cylinder head core plug
installer, J 34684 for 13/16-inch (20.64 mm)
cup plugs, and J 34687 for 1-1/16 inch
(26.99 mm) cup plugs. Refer to Figure 207.
Cup plug should be installed flush with the
cylinder head machined surface to 0.020 inch
(0.508 mm) below the surface.
207
Figure 207 — Cylinder Head Cup Plug Installation
Cylinder Head Pipe Plug
Replacement
GENERAL INFORMATION
The 3/4-inch cylinder head pipe plugs sealed with
a teflon-based thread sealer may loosen and
result in a coolant leak after initial installation.
Beginning April 1, 1999 (engine serial number
series 9F), 3/4-inch pipe plugs having a
preapplied encapsulated epoxy sealant were
phased into engine production. With the epoxy
sealer, the pipe plugs are locked into place,
making them immovable when normal loosening/
tightening methods are used. Should it become
necessary to remove a pipe plug, the following
procedure should be used.
If a cylinder head has been placed in a hot
chemical tank for cleaning and degreasing, the
pipe plugs must be checked for looseness. If a
plug is found to be loose, the epoxy seal has
been broken, making it necessary to remove the
plug, clean the plug and cylinder head threads
with Loctite
®
Primer T and reseal the threads with
Loctite
®
277.
If coolant leaks at the cylinder head pipe plugs
are encountered on engines manufactured prior
to engine serial number series 9F, the pipe plugs
must be removed, cleaned and reinstalled
following the procedures below.
REPLACEMENT (3/4-INCH PLUGS)
Refer to Figure 208.
1. Heat the pipe plug to 400
°
F (205
°
C) with a
torch.
2. With the pipe plug heated sufficiently,
remove the plug from the cylinder head.
3. Remove the epoxy sealant from the threads
on both the plug and in the cylinder head.
4. Clean the plug and cylinder head threads
with Loctite
®
Primer T.
5. Apply Loctite
®
277 sealant to the plug and
cylinder head threads.
6. Install the plugs and tighten to the specified
torque, 55 lb-ft (68 N•m).
1. Cup Plug
2. Cup Plug Installer
5_106_00.bk Page 200 Friday, August 4, 2000 11:17 AM
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