General Information
The exhaust system must be free of leaks, binding, grounding, and excessive vibrations. These conditions are usually caused by loose, broken, or misaligned clamps, brackets, or pipes. If any of these conditions exist, check the exhaust system components and alignment. Align or replace as necessary; see of the Western Star 47X and 49X Workshop Manual.
It is a violation of US federal law to alter exhaust plumbing or aftertreatment in any way that would bring the engine out of compliance with certification requirements. (Ref: 42 U.S.C. S7522(a) (3).) It is the owner's responsibility to maintain the vehicle so that it conforms to EPA regulations.
No visible exhaust gas leaks are allowed anywhere in the ATS. If any problems are discovered, refer to the engine manufacturer's service literature for repair instructions.
- Check the DEF tank, pump, metering unit, and lines for leaks. See Section 49.02 of the Western Star 47X and 49X Workshop Manual for repair procedures.
- Check any wires, lines, or hoses within 4 inches (10 cm) of any uninsulated part of the exhaust system for heat damage. Repair or reroute as needed.
Note: Diesel exhaust fluid creeps, causing white crystals to form around the line fittings. The presence of crystals does not mean the system has a leak. Replacing fittings or troubleshooting components is not necessary unless there is a system failure or a fault code.