Centinel System – Repair Manual – 010-024   Air Leaks, Air Intake and Exhaust Systems

CAUTION  Engine intake air must be filtered to prevent dirt and debris from entering the engine. If intake air piping is damaged or loose, unfiltered air will enter the engine and cause premature wear.

Inspect for loose clamps or damage between the intake air piping, air cleaner, turbocharger, charge-air cooler, and intake manifold.

Check for corrosion of the intake system piping under the clamps and hoses. Corrosion can allow corrosive products and dirt to enter the intake system. Disassemble and clean as required.

Replace damaged pipes and tighten loose clamps.

Excessive back pressure can cause exhaust leaks. Verify the exhaust back pressure is within specified limits. Refer to Procedure
011-009.

Operate the engine at full throttle and maximum load, and check for air leaks. Listen for a whistling noise caused by high-pressure air leaks.

CAUTION  Do not use air tools to remove or install the nut on the v-band clamp. Use of these tools can seriously damage the threads or the bolt and cause the clamp to not be able to be reused.

The noise can be caused by an air leak from the following:

Turbocharger-to-charge-air cooler elbow connection.

• Inspect the connection and o-ring for damage.
• Tighten the v-band clamps.

Any charge-air cooler piping or connecting hose.

• Inspect the hose and piping for damage.
• Tighten the hose clamps.

Turbocharger-to-exhaust-manifold mounting gasket.

• Replace the gasket.

Refer to Procedure
010-033 for turbocharger removal and installation.

CAUTION  Do not use air tools to remove or install the nut on the v-band clamp. Use of these tools can seriously damage the threads or the bolt and cause the clamp to not be able to be used.

Turbine housing sealing surface air leak.

• Tighten the v-band clamp.

• Check for an air leak.
• If an air leak is still present, remove and replace the turbocharger.

Compressor housing sealing surface air leak.

• Tighten the v-band.

• Check for an air leak.
• If an air leak is still present, remove and replace the turbocharger.

Check for soot streaks from the EGR connection tubes and hoses.

• Tighten the hose clamps. Refer to Procedure
  011-025.
• Check for an exhaust leak. If an exhaust leak is still present, remove and replace the EGR crossover tube or hose.

Check for leakage from the EGR valve weep hole.

• Soot leakage at the EGR valve weep hole is normal and is expected. Do
  not replace the EGR valve if soot streaks are found at the EGR valve weep hole.

Check for soot streaks from the EGR connection tubes and hoses.

• Tighten the hose clamps. Refer to Procedure
  011-025. Check for an exhaust leak. If an exhaust leak is still present, remove and replace the EGR crossover tube or hose.

Check for soot streaks from the EGR valve gasket and seal rings.

• Inspect for signs of leakage such as soot streaks. If signs of leakage are present, replace the EGR valve gaskets. Refer to Procedure
  011-022.

Check for leakage from the EGR valve weep hole.

• Soot leakage at the EGR valve weep hole is normal and is expected. Do
  not replace the EGR valve if soot streaks are found at the EGR valve weep hole.

Check for leakage from the EGR cooler bellows.

• Inspect for signs of leakage such as soot streaks. If signs of leakage are present, replace the EGR cooler or gaskets. Refer to Procedure
  011-019.

Check for soot leakage at the EGR differential pressure sensing tubes.

• Inspect for signs of leakage such as soot streaks which may appear yellowish brown or black. If signs of leakage are present, replace the EGR differential pressure tubes. Refer to Procedure
  011-026.

Check for soot leakage on the exhaust adapter pipe.

• Inspect for signs of leakage such as soot streaks which may appear yellowish brown or black. If signs of leakage are present, replace the gasket and v-band clamp. Refer to Procedure
  011-007 for the bellows and Procedure
  011-019 for the exhaust manifold.

Clean all soot stains and paint the components in order to detect future leaks.

Check the aftertreatment adapter pipe.

• Inspect for visible soot streaks at the v-band joint.

If soot streaks are found, tighten the v-band clamp. Refer to Procedure
011-043.

Operate the engine at full throttle and check for leakage at full throttle condition.

If a leak is still present, remove and replace the gasket with a new gasket and a new v-band clamp.

Check the aftertreatment inlet connection.

• Inspect for visible soot streaks at the torca clamp or v-band clamp joint. Also inspect for loose or damaged insulation wrapping (if applicable).

If soot streaks are found, tighten the v-band or torca clamp. Refer to Procedure
011-041.

Operate the engine at full throttle and check for leakage at full throttle condition.

If a leak is still present, remove and replace the clamp with a new torca clamp or v-band clamp.

Check the inlet to catalyst connection.

• Inspect for visible soot streaks at the v-band joint.

If soot streaks are found, check for fault codes relating to high differential pressure in the aftertreatment system. If no fault codes are found, tighten the v-band clamp. Refer to Procedure
011-050.

Operate the engine at full throttle and check for leakage at full throttle condition.

If a leak is still present, remove and replace with a new gasket and v-band clamp.

Check the catalyst to aftertreatment particulate trap connection.

• Inspect for visible soot streaks at the v-band joint.

If soot streaks are found, check for fault codes relating to high differential pressure in the aftertreatment system. If no fault codes are found, tighten the v-band clamp. Refer to Procedure
011-049.

Operate the engine at full throttle and check for leakage at full throttle condition.

If a leak is still present, remove and replace the gasket with a new gasket and v-band clamp.

Check the aftertreatment diesel particulate filter to outlet connection.

• Inspect for visible soot streaks at the v-band joint.

If soot streaks are found, check for fault codes relating to high differential pressure in the aftertreatment system. If no fault codes are found, tighten the v-band clamp. Refer to Procedure
011-041.

Operate the engine at full throttle and check for leakage at full throttle condition.

If a leak is still present, remove and replace with a new gasket and v-band clamp.

Check the aftertreatment outlet connection.

• Inspect for visible soot streaks at the v-band joint.

If soot streaks are found, check for fault codes relating to high differential pressure in the aftertreatment system. If no fault codes are found, tighten the v-band clamp. Refer to Procedure
011-041.

Operate the engine at full throttle and check for leakage at full throttle condition.

If a leak is still present, remove and replace with a new gasket and v-band clamp.

Check the aftertreatment diesel particulate filter differential pressure sensor tube connections.

• Inspect for visible soot streaks at the threaded bosses or hose connections.

If soot streaks are found at the threaded boss, loosen the differential pressure sensor tube nut, apply a coating of anti-seize compound, and tighten the differential pressure sensor tube nut. Refer to Procedure
011-047.

If soot streaks are found at the hose connections, remove and connect hose. Refer to Procedure
011-047.

Operate the engine at full throttle and check for leakage at full throttle condition.

If a leak is still present at the threaded boss, remove and replace the differential pressure sensor tube.

If a leak is still present at the hose connection, replace the differential pressure sensor tube or differential pressure sensor, depending on which component the hose is permanently attached to.

If damage resulted in coolant, oil, excessive fuel or excessive black smoke entering the exhaust system, the aftertreatment system
must be inspected. Refer to Procedure
014-013.