Caution: Do not use caustic or acid solutions to clean the cylinder head capscrews.
Use a petroleum-based solvent to clean the capscrews.
Clean the capscrews thoroughly with a wire brush, with a wire wheel (soft), or use a non-abrasive bead blast to
remove deposits from the shank and the threads.
Visually inspect the cylinder head capscrews for dam- aged threads, corroded surfaces, or a reduced diameter
(due to capscrew stretching).
NOTE: Do not reuse a capscrew that has damaged threads or a reduced diameter from having been stretched.
Do not reuse cylinder head capscrews under the following conditions:
• Visible corrosion or pitting exceeds 1 sqcm [0.155 sq. inch] in area. Example:
• Acceptable 3/8-x3/8-inch
• Unacceptable 1/2-x1/2-inch
• Visible corrosion or pitting exceeds 0.12 mm [0.005-inch] in depth.
• Visible corrosion or pitting is located within 3.2 mm [1/8-inch] of the fillet.
• Visible corrosion or pitting is located within 3.2 mm [1/8-inch] of the threads.
Using flange head capscrews with the torque plus angle method of installation places the capscrew beyond the
yield point, and permanently stretches the capscrew at each use. These capscrews can be reused throughout the
life of the engine unless the capscrew exceeds the specified free length. The capscrew free length must be
checked to avoid bottoming out in the cylinder block during installation.
Use service tool, Part No. 3823546, to check capscrew free length.
The capscrews can be checked using a set of calipers if service tool, Part No. 3823546, is not available. The max-
imum allowable free length (dimension ‘X’), measured from the bottom of the flange to the end of the capscrew,
is 185.6 mm [7.130 in].
To check the capscrew free length, place the head of the capscrew in the appropriate slot with the flange against
the base of the slot.
NOTE: Capscrew length must be checked without the hardened washer.
If the end of the capscrew touches the foot of the gauge, the capscrew is too long and must be discarded.
The capscrew can be used again if there is clearance between the end of the capscrew and the bottom base of
the tool.
Immediately after cleaning and inspecting, apply a film of clean engine lubricating oil to capscrews that are to be
used again.
