To determine if a worn or damaged cylinder kit is causing excessive crankcase pressure, perform
the following:
1. Move the vehicle requiring testing 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 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 form the chassis dynamometer.
10. Review the crankcase pressure test. For crankcase pressure guidelines refer to Service
Information Letter 02 TS-20 found on the DDC extranet.
[a] If the crankcase pressure was greater than 1.25 kPa (5 in. H2O), refer to section 9.2.1.
[b] If the crankcase pressure was less than 1.25 kPa (5 in. H2O), perform a cylinder
compression test. Refer to section 9.2.1.2.
11. Compare the cylinder compression test results to specifications.
[a] If cylinder pressure is below specifications, refer to section 9.2.1.
[b] If cylinder pressure is within specifications, call Detroit Diesel Customer Support
Center (313-592-5800).
9.2.1
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, pistons, or piston roings;
refer to appropriate service manual, engine chapter.
4. Verify repair to cylinder valve(s) or cylinder kit components; refer to section 9.2.1.1.
9.2.1.1
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. Refer to section9.2 for exhaust caution before proceeding. Start the engine.
2. Run the engine and bring the engine coolant temperature to normal operating range,
88-96°C (190-210°F).
3. Run the vehicle to full load and rated speed.
4. Visually inspect exhaust for excessive smoke.
[a] If the engine exhaust smoke emission appears normal, no further troubleshooting is
required. Shut down the engine.
[b] If the engine exhaust smoke is excessively black or gray, call the Detroit Diesel
Customer Support Center (313-592-5800). Shut down the engine.
9.2.1.2
Cylinder Compression Test
