TM-9-2815-202-34 Technical Manual for 8V71T Engines for M109 Howitzer Download
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(5) (6) Immerse cylinder head in a tank of water heated to 180 o -200 o F (82 o -93 o C) for twenty minutes to heat head. Observe water in tank for bubbles which indicate a leak or crack. Check for leaks at top and bottom of injector tubes, oil gallery, exhaust ports, fuel galleries, and at top and bottom of cylinder head. Relieve air pressure and remove cylinder head from water tank. Remove regulated air supply, end plate, injectors, and blocking plates from cylinder head. d. Inspection/Repair NOTE If warpage exceeds limits, reface cylinder head. Do not remove more metal from fire deck than minimum distance of 3.536 inches from top of deck to bottom of fire deck. (1) Cylinder head (a) (b) Check fire deck surface of cylinder head for flatness. Using a straight edge (66) and a set of feeler gages (67), check lengthwise (six places) and crosswise (five places) warpage. Maximum lengthwise warpage is 0.008 inch and maximum crosswise warpage is 0.004 inch. Inspect cam follower bores in cylinder head for scoring and wear. Clean light score marks with crocus cloth wet with fuel oil. Measure diameter of cam follower body and cam follower bore to determine clearance. Maximum clearance is 0.006 inch. Replace cylinder head if bores are excessively worn or scored. (2) Water nozzles Check water hole nozzles (68 and 69) for looseness. If necessary, replace nozzles as follows: (a) Remove old nozzle (68 or 69) and clean bore in cylinder head. TM 9-2815-202-34 4-191