DOT INSPECTION-EXHAUST & FUEL SYSTEM

Fuel system is a combinations of parts needed to carry fuel into and out of the engine.  The following defects should be inspected for during your daily inspection of your commercial vehicle:

• Visible leaks at any point
• Missing fuel tank filler cap
• Loose, broken, or missing mounting bolts or brackets that result in a fuel tank not being securely attached to the motor vehicle (some fuel tanks use springs or rubber bushings to permit movement)

Exhaust system is a system consisting of the parts of an engine through which burned gases or steam are discharged. The exhaust system leaks at a point forward of, or directly below, the driver or sleeper compartment.

​No part of the exhaust system of any motor vehicle may be located where it's likely to cause burning, charring, or damaging the electrical wiring, the fuel supply, or any combustible part of the motor vehicle.

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Federal Motor Carrier Safety Administration Q & A

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Guidance for § 393.83: Exhaust systems.

Question 1: Is a heat shield mandatory on a vertical exhaust stack?

Guidance: No. However, §393.83 requires the placement of the exhaust system in such a manner as to prevent the burning, charring, or damaging of the electrical wiring, the fuel supply, or any combustible part of the Commercial Motor Vehicle (CMV).

Question 2: Does §393.83 specify the type of exhaust system, vertical or horizontal, to be used on trucks or truck tractors?

​Guidance: No.
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Guidance for § 393.65: All fuel systems.

​Question 1: May a fuel fill pipe opening be placed above the passenger floor level if it is not physically within the passenger compartment?

​Guidance: Guidance: Yes. In addition, the fill pipe may intrude into the passenger compartment as long as the fill pipe opening complies with §390.5 because it transports hazardous materials in a quantity requiring placarding under the Hazardous Materials Regulations (49 CFR parts 171-180) comply with the fuel system requirements of Subpart E of Part 393, even though it has a gross vehicle weight rating (Gross Vehicle Weight Rating (GVWR)) of 10,000 pounds or less?

Guidance: Guidance: No. Federal Motor Vehicle Safety Standards (developed and issued by the NationalHighway Traffic Safety Administration) FMVSS No.301 contains fuel system integrity requirements for passenger cars and multipurpose passenger vehicles, trucks, and buses that have a Gross Vehicle Weight Rating (GVWR) of 10,000 pounds or less and use fuel with a boiling point above 0 deg. Celsius (32 deg. Fahrenheit). Subpart E of Part 393 was issued to provide fuel system requirements to cover motor vehicles with a GVWR of 10,001 or more pounds. The fuel systems of placarded motor vehicles with a GVWR of less than 10,001 pounds are adequately addressed by FMVSS No. 301 and compliance with subpart E of part 393 would be redundant. However, commercial motor vehicles that are not covered by FMVSS No. 301 must continue to comply with Subpart E of Part 393.