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SERIES 50 WORN OR DAMAGED VALVE OR CYLINDER KIT

A loss of cylinder pressure can cause increased oil consumption. The detection and elimination of cylinder pressure losses is vital to engine life and efficient operation. To assist the mechanic in effectively measuring the loss of cylinder pressure, and locating the source of abnormal leaks in individual cylinders, the following test procedure has been developed. ‪

  1. Move the vehicle requiring test to the chassis dynamometer; refer to OEM guidelines.
  2. Disconnect air compressor, refer to Section .
  3. Start the engine.
  4. Run the engine and bring the engine coolant temperature to normal operating range.
  5. Run vehicle to full load and rated speed.
  6. Attach a manometer, refer to Section , calibrated to read in inches of mercury, to the oil dipstick opening. Measure and record the crankcase pressure; refer to Section .
  7. Shut down engine.
  8. Remove the vehicle from the chassis dynamometer.
  9. Review the crankcase pressure test results.
    1. If the crankcase pressure exceeds 3 in. H2 O (0.75 kPa), repair worn or damaged valve(s) or cylinder kit; refer to Section .
    2. If the crankcase pressure was less than or equal to 3 in. H2 O (0.75 kPa), perform cylinder compression test; refer to Section .
  10. Compare the cylinder compression test results to specifications.
    1. If the cylinder compression is below specifications, repair worn or damaged valve(s) or cylinder kit; refer to Section
    2. If the cylinder compression is within specification, call Detroit Diesel Technical Service Group.

Worn or Damaged Valve(s) or Cylinder Kit(s) Repair

Perform the following steps to repair worn or damaged valve(s) and cylinder kit(s): ‪

  1. Remove cylinder head; refer to Section .
  2. Inspect the cylinder head for worn or damaged valves; refer to Section .
  3. Inspect for worn or damaged cylinder kit components:
    1. Inspect cylinder liner for damage, refer to Section .
    2. Inspect piston and piston rings for damage, refer to Section .
  4. Perform an oil consumption test report; refer to Section .
Test Engine for Reduced Oil Consumption

Perform a lube oil consumption report; refer to Section . ‪

  1. Review the oil consumption report.
    1. If the oil consumption report data is within specifications, check for defective air compressor. Refer to Section .
    2. If the oil consumption report data is not within specifications, call Detroit Diesel Technical Service Group.