TM-9-2320-361-24-1 Field Maintenance Manual Volume 1 for M44A2 Series Trucks
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TM 9-2320-361-24-1 0008 00 0008 00-6 MECHANICAL SYSTEMS TROUBLESHOOTING - DIRECT SUPPORT (Contd) MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 11. EXHAUST COLOR BLUE DURING NORMAL OPERATION (Contd) 6. Crank engine through at least five compression strokes or until gauge stops rising. 7. Record cylinder number and maximum gauge reading. 8. Remove gauge from number 1 cylinder and repeat steps 1 through 7 for remaining cylinders. This is known as a dry test. 9. Add 1 to 1 ½ oz (29–44 ml) of clean engine oil through plug port for each cylinder before connecting compression gauge. Repeat steps 5 through 7. This is known as a wet test. 10. Record gauge readings for wet test next to dry recorded test results for each cylinder. Test 2. Analyze compression test results. Compute compression loss for dry test for each cylinder compared to cylinder with highest reading using the following formula: 1. If one or more cylinders has an 8–10% or greater compression loss in dry test, but improved to acceptable (less than 8%) loss in wet test, then pistons, piston rings, or cylinder liners problem is indicated. 2. Remove heads and inspect pistons, piston rings, and cylinder liners for breaks, wear and scoring. If pistons, piston rings, or cylinder liners are damaged, replace engine (WP 0046 00). If damaged, replace engine (WP 0046 00). Table 1. Engine Troubleshooting Procedures (Contd). NOTE The sample cylinder reading is the reading from any cylinder other than the highest compression cylinder. Highest Sample Cylinder Reading – Cylinder Reading x 100 = % Compression Loss Highest Cylinder Reading