Section 8.4 Worn or Damaged Valve or Cylinder Kit

Section 8.4
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. Remove air compressor; refer to the MBE 4000 Service Manual (6SE420), Chapter 6, “Air Intake System”.

   PERSONAL INJURY ‪
   To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

3. Start the engine.
4. Run the engine and bring the engine coolant temperature to normal operating range, approximately 88-96°C (190-205°F).
5. Run the vehicle to full load and rated speed.
6. Measure and record crankcase pressure. refer to "2.1 Crankcase Pressure Test" .
7. Shut down the engine.
8. Remove the vehicle from the chassis dynamometer.
9. Review the crankcase pressure test.
   1. If the crankcase pressure is greater than 0.62 kPa (2.5 in. H ₂ O), go to step 10 .
   2. If the crankcase pressure is less than 0.62 kPa (2.5 in. H ₂ O), no further troubleshooting is required.
10. Perform the cylinder compression test, Refer to "2.2 Compression Pressure Test" .
    1. If cylinder compression pressure is below specifications, Refer to "8.4.1 Worn or Damaged Valve or Cylinder Kit Repair" .
    2. If cylinder compression pressure is within specifications, call Detroit Diesel Customer Support Center at 313-592-5800.

Section 8.4.1
Worn or Damaged Valve or Cylinder Kit Repair

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

1. Remove the cylinder head; refer to theMBE 4000 Service Manual (6SE420), Chapter 1, “Engine — cylinder head.
2. Inspect the cylinder head for worn or damaged valves; MBE 4000 Service Manual (6SE420), Chapter 1, “Engine — cylinder head.
3. Inspect the cylinder kit components for worn or damaged liners, piston or piston rings; refer to the MBE 4000 Service Manual (6SE420), Chapter 1, “Engin”.
4. Verify repair to cylinder valve(s) or cylinder kit components; refer to "8.4.1.1 Test Engine with Repairs Made to Correct Worn or Damaged Valve or Cylinder Kit"

Section 8.4.1.1
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 the MBE 4000 Service Manual (6SE420), Chapter 11, “Special Equipment”.

   PERSONAL INJURY ‪
   To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

3. Start the engine.
4. Run the engine and bring the engine coolant temperature to normal operating range, approximately 88-96°C (190-205°F).
5. Run the vehicle to full load and rated speed.
6. Measure and record crankcase pressure. refer to "2.1 Crankcase Pressure Test" .
7. Shut down the engine.
8. Remove the vehicle from the chassis dynamometer.
9. Compare the cylinder compression pressure test results to specifications listed in table "Compression Pressure Test Data"
   1. If cylinder compression pressure is within specifications, no further troubleshooting is required.
   2. If cylinder compression pressure is not within specifications, call Detroit Diesel Customer Support Center at 313-592-5800.

      Description‪	Pressure in kPa (psi)‪
      Compression Pressure at Starter Speed‪	2800 (406)‪
      Permissible Difference between Individual Cylinders‪	400 (58)‪

      Table 3. Compression Pressure Test Data