MBE 4000 DDEC VI Troubleshooting – Section 9.11 Faulty Exhaust Brake Gate

Section 9.11
Faulty Exhaust Brake Gate

To determine if a faulty exhaust brake gate is causing excessive black or gray smoke, check exhaust brake valve for freedom of movement.‪

1. If movement is not free, replace exhaust brake gate; refer to MBE 4000 Service Manual) (6SE420, Chapter 7, “Exhaust System – Brake Gate”. Verify replacement of the exhaust brake gate; refer to "9.11.1 Test Engine for Replaced Exhaust Brake Gate" .
2. If movement is free, check the exhaust brake cylinder; refer to "9.12 Faulty Exhaust Brake Gate Actuator" .

Section 9.11.1
Test Engine for Replaced Exhaust Brake Gate

Perform the following steps to determine if the replaced exhaust brake gate resolved the excessive exhaust smoke condition:‪

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.‪

1. Start and run the engine.
2. Run the engine at idle under no-load conditions for approximately five minutes, allowing the engine coolant to reach normal operating range, approximately 88-96°C (190-205°F).
3. Visually inspect exhaust for excessive smoke.
   1. If the engine smoke emission appears normal, no further troubleshooting is required. Shut down the engine.
   2. If the engine exhaust smoke is excessively black or gray, shut down the engine. Check the exhaust brake gate actuator; refer to "9.12 Faulty Exhaust Brake Gate Actuator" .