5-43. CYLINDER BLOCK - MAINTENANCE INSTRUCTIONS (Continued).
a. Scrape all gasket material from the cylinder block. Then remove all oil gallery
plugs and core hole plugs (except cup plugs) to allow the cleaning solution to
contact the inside of the oil and water passages. This permits more efficient
cleaning and eliminates the possibility of the cleaning solution attackin the
aluminum core hole plug gaskets (if used).
b. If a core hole plug is difficult to remove, hold a inch drift against the plug and give
it a few sharp blows with a one pound hammer. With a 1/2 inch flexible handle and
a short extension placed in the countersunk hole in the plug, turn the plug slightly
in the direction of tightening. Then turn it in the opposite direction and back the
plug out. To remove the special plugs in the water-below-port cylinder block:
Clean the cylinder block as follows:
(1) Remove the grease by agitating the cylinder block in a hot bath of commercial
heavy-duty alkaline solution.
(2) Wash the block in hot water or steam clean it to remove the alkaline solution.
(3) If the water jackets are heavily scaled, proceed as follows:
Agitate the block in a bath of inhibited commercial pickling acid.
Allow the block to remain in the acid bath until the bubbling stops
(approximately 30 minutes).
Lift the block, drain it and re-immerse it in the same acid solution for 10
Repeat Step (c) until all scale is removed.