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 appropriate service manual, special equipment chapter.
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 calibrated to read in inches of water, to the oil dipstick opening. Measure and record the crankcase pressure.
7. Shut down engine.
8. Remove the vehicle from the chassis dynamometer.
9. Review the crankcase pressure test results.
[a] If the crankcase pressure exceeds 1.25 kPa (5 in. H2O), repair worn or damaged
valve(s) or cylinder kit; refer to section 7.4.1.
[b] If the crankcase pressure was less than or equal to 1.25 kPa (5 in. H2O), perform
cylinder compression test.Refer to section 7.4.1.2.
10. Compare the cylinder compression test results to specifications.
[a] If the cylinder compression is below specifications, repair worn or damaged valve(s)
or cylinder kit; refer to section 7.4.1.
[b] If the cylinder compression is within specification, call Detroit Diesel Customer
Support Center (313-592-5800).
7.4.1
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 appropriate service manual, engine chapter.
2. Inspect the cylinder head for worn or damaged valves; refer to appropriate service manual, engine chapter.
3. Inspect the cylinder kit components for worn or damaged liners, piston, or piston rings;
refer to appropriate service manual, engine chapter.
4. Verify repair to cylinder valve(s) or cylinder kit components; refer to section 7.4.1.1.
7.4.1.1
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 appropriate service manual, special equipment chapter.
3. Refer to section7.4 for exhaust caution before proceeding. 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 calibrated to read in inches of water, to the oil dipstick opening.
7. Measure and record crankcase pressure. For crankcase pressure guidelines refer to Service
Information Letter 02 TS-20 found on the DDC extranet.
8. Shut down the engine.
9. Remove the vehicle from the chassis dynamometer.
10. Compare the cylinder pressure test results to specifications.
[a] If cylinder pressure is within specifications, no further troubleshooting is required.
[b] If cylinder pressure is not within specifications, call Detroit Diesel Customer Support
Center at 313–592–5800.
7.4.1.2
Cylinder Compression Test
