Series 50 – Section 20.4 Worn or Damaged Valve or Cylinder Kit

Section 20.4
Worn or Damaged Valve or Cylinder Kit

To determine if a worn or damaged cylinder kit is causing excessive crankcase pressure, perform the following:‪

1. Move the vehicle requiring test to the chassis dynamometer; refer to OEM guidelines.
2. Disconnect air compressor; refer to "10.1.2 Cleaning and Removal of Air Compressor" .
3. Start the engine.
4. Run the engine and bring the engine coolant temperature to normal operating range.
5. Run the vehicle to full load and rated speed.
6. Attach a manometer, refer to "29.1 Proper Use of Manometer" , calibrated to read in inches of water, to the oil dipstick opening.
7. Measure and record crankcase pressure.
8. Shut down the engine.
9. Remove the vehicle from the chassis dynamometer.
10. Review the crankcase pressure test.
    1. If the crankcase pressure was greater than 3 in. H₂ O (0.75 kPa); refer to "20.4.1 Worn or Damaged Valve or Cylinder Kit Repair" .
    2. If the crankcase pressure was less than 3 in. H₂ O (0.75 kPa); perform a cylinder compression test; refer to "29.2 Cylinder Compression Test" .
11. Compare the cylinder compression test results to specifications.
    1. If cylinder pressure is below specifications, (listed in Table "Compression Pressures at Various Altitudes" , refer to "29.2 Cylinder Compression Test" ); refer to "20.4.1 Worn or Damaged Valve or Cylinder Kit Repair" .
    2. If cylinder pressure is within specifications, (listed in Table "Compression Pressures at Various Altitudes" , refer to "29.2 Cylinder Compression Test" ), call Detroit Diesel Technical Service Group.

Section 20.4.1
Worn or Damaged Valve or Cylinder Kit Repair

Perform the following steps for worn or damaged valve or cylinder kit:‪

1. Remove the cylinder head; refer to "1.2.2 Removal and Cleaning of Cylinder Head" .
2. Inspect the cylinder head for worn or damaged valves; refer to "1.2.3 Inspection of Cylinder Head" .
3. Inspect for worn or damaged cylinder kit components:
   1. Inspect cylinder liner for damage, refer to "1.20.1 Repair or Replacement of Cylinder Liner" .
   2. Inspect piston and piston rings for damage, refer to "1.18.1 Repair or Replacement of Piston and Connecting Rod" .
4. Verify repair to cylinder valve(s) or cylinder kit components; refer to "20.4.1.1 Test Engine with Repairs Made to Correct Worn or Damaged Valve or Cylinder Kit" .

Section 20.4.1.1
Test Engine with Repairs Made to Correct Worn or Damaged Valve or Cylinder Kit

Perform the following to determine if the repaired valve or cylinder kit resolved the excessive crankcase pressure:‪

1. Move the vehicle requiring test to the chassis dynamometer; refer to OEM guidelines.
2. Disconnect air compressor; refer to "10.1.2 Cleaning and Removal of Air Compressor" .
3. Start the engine.
4. Run the engine and bring the engine coolant temperature to normal operating range.
5. Run the vehicle to full load and rated speed.
6. Attach a manometer, refer to "29.1 Proper Use of Manometer" , calibrated to read in inches of water, to the oil dipstick opening.
7. Measure and record crankcase pressure.
8. Shut down the engine.
9. Remove the vehicle from the chassis dynamometer.
10. Compare the cylinder pressure test results to specifications.
    1. If cylinder pressure is within specifications, (listed in Table "Compression Pressures at Various Altitudes" , refer to "29.2 Cylinder Compression Test" ), no further troubleshooting is required.
    2. If cylinder pressure is not within specifications, (listed in Table "Compression Pressures at Various Altitudes" , refer to "29.2 Cylinder Compression Test" ), call Detroit Diesel Technical Service Group.