TM 10-3930-660-34 3-6. CYLINDER BLOCK - REPLACE (Cont’d) 2. REMOVE TWO PIPE PLUGS (3) AND ONE PIPE PLUG (4). 3. REMOVE AND DISCARD THREE CUP PLUGS (5) FROM OIL PASSAGES. a. Drill hole in center of each cup plug (5) using suitably sized drill bit. b. Remove cup plugs (5) using a slide hammer, or other suitable tool. Discard cup plugs (5). 4. REMOVE AND DISCARD SIX CUP PLUGS (6) AND FOUR CUP PLUGS (7) FROM COOLANT PASSAGES. a. Tap against center of each cup plug (6 or 7) using a punch and a hammer. b. Grasp cup plug (6 or 7) with a plier and remove from bore. Discard cup plugs (6 and 7). 5. REMOVE TWO SCREWS (8),OIL FILLER PIPE (9) AND O-RING (10).DISCARD O-RING (10). 6. REMOVE MISCELLANEOUS PARTS FROM CYLINDER BLOCK. a. Remove two dowel rings (11) and two dowel rings (12). b. Remove fourteen bolts (13) and seven main bearing caps (14). Remove fourteen dowel rings (15), if necessary. c. Remove two expansion plugs (16). d. Remove two dowel pins (17),if necessary. e. Remove six piston cooling nozzles (18). CLEANING CAUTION Do not clean cylinder block in an acid bath unless camshaft bushing (1) has been removed. An acid bath can severely damage camshaft bushing. 1. SOAK CYLINDER BLOCK IN AN ACID BATH, IF CAMSHAFT BUSHING (1) HAS BEEN REMOVED, AND IF HEAVY DEPOSITS EXIST IN COOLANT PASSAGES. 2. IF CAMSHAFT BUSHING (1) HAS NOT BEEN REMOVED, AND COOLANT PASSAGES HAVE HEAVY DEPOSITS, SOAK CYLINDER BLOCK IN A SOLUTION OF HOT WATER AND LAUNDRY DETERGENT. MAINTAIN WATER TEMPERATURE OF 1900 F (880 C) AND ALLOW CYLINDER BLOCK TO SOAK FOR A PERIOD OF 30 MINUTES. 3. FOLLOWING CLEANING BY EITHER METHOD(STEP 1 OR 2),RINSE THOROUGHLY WITH CLEAN, FRESH WATER AND ALLOW SURFACE TO DRY COMPLETELY. 4 IF A SIZING HONE IS USED TO CORRECT A MINOR CYLINDER BORE TAPER OR TO REMOVE MINOR GROOVES IN CYLINDER WALLS, IMMEDIATELY CLEAN BORES USING A STRONG SOLUTION OF LAUNDRY DETERGENT AND HOT WATER. RINSE THOROUGHLY WITH CLEAR WATER. 5. AFTER RINSING AND DRYING CYLINDER BORES, WIPE BORES WITH WHITE, LINT- FREE CLOTH THAT IS LIGHTLY OILED.  IF GRIT RESIDUE IS PRESENT ON CLOTH, CLEAN BORES AGAIN IN DETERGENT SOLUTION. INSPECTION 1. CHECK FLATNESS OF CYLINDER BLOCK TOP SURFACE. a. Place a straightedge along length of cylinder block top. 3-31