DD15 Engine Brake Check

Use this procedure to determine the cause of poor engine brake performance when no codes are present. ‪

Check as follows:‪

1. Check the oil pressure using DDDL 7.0 or later.
   1. If the oil pressure is OK, go to the next step.
   2. If the oil pressure is low, refer to “14.1.1 Oil Pressure Check” .
2. Check valve lash and engine brake adjustment.
   1. If valve lash is OK and the engine brake is in adjustment, go to the next step.
   2. If either are out of adjustment, readjust them and retest.
3. Inspect the exhaust rocker shaft to ensure it is installed with the groove toward the rear of the engine near the cam gear.
   

   NOTICE:
   The cam journal area is lubricated by oil that has to travel through the rocker shaft. If the shaft is installed incorrectly, oil passages do not line up. This results in insufficient lubrication and damage to the cam journals.‪

   

   1. Marking Groove – faces rear of engine‪

   ‪

   1. If the exhaust rocker shaft is correctly installed, check the cam timing. Refer to “8.5 Camshaft Timing Verification” .
   2. If the exhaust rocker shaft is incorrectly installed, check the cams and valve train for damage. Replace damaged parts.

Oil Pressure Check

Check as follows:‪

1. Start engine and check oil pressure.
   1. If pressure is fluctuating, go to the next step.
   2. If pressure is low but stable, go to step 3 .
2. Stop the engine and allow sufficient time for the oil to drain into the oil pan. Perform the following steps:
   1. Check the oil level. Add recommended oil to bring it to the proper level, if required.
   2. Check for faulty oil gage. Replace, if required.
   3. Check for loose or cracked oil pump suction pipe. Repair or replace, as required.
   4. Check for loose drive or driven oil pump gear. Repair or replace, as required.
   5. Check for faulty oil pressure relief valve. Repair or replace, as required.
   6. Refer to “25.4.1 Verify Repairs” .
3. Stop the engine and allow sufficient time for the oil to drain into the oil pan. Check the oil level.
   1. If oil is above maximum level with no oil previously added, go to the next step.
   2. If oil is not above maximum level, contact Detroit Diesel Customer Support Center (313–592–5800).
4. Check for possible fuel in oil.
   1. If fuel is found, locate and repair source of fuel leak. Change the oil. Refer to “25.4.1 Verify Repairs” .
   2. If fuel is not found, contact Detroit Diesel Customer Support Center at 313–592–5800.