• AMBW
  • Motor Age
  • Motor Age Training
  • Professional Distributor
  • PTEN
    1. Service Repair
    2. Video Network
    3. The Trainer

    The Trainer #154: EVAP system leak diagnosis using a pressure transducer

    Nov. 26, 2024
    EVAP system leak diagnosis was simple when leaks are large but with today's stringent leak detection requirements, the Digital Dual Smoke Machine from Master Cool makes light work of them!

    For decades now, technicians across the globe have struggled to efficiently pinpoint pesky and minute EVAP system leaks. In earlier days, when emissions standards were not as stringent, ECMs/PCMs were only obligated to detect EVAP system leaks of 0.020” in diameter. With that, a smoke machine was a common and capable tool to locate leaks of that size.

    However, as time passed and emissions standards grew more stringent, the leaks ECMs/PCMs had to detect from the EVAP systems grew smaller. By today’s standards, a leak no larger than 0.010” in diameter is what ECMs/PCMs must accurately detect. They do so by employing a detection strategy known as Engine-Off Natural Vacuum Leak Detection. This strategy capitalizes on physics. More notably, Boyle’s Ideal Gas Law. The law states that a sealed system should begin to pressurize as the temperature begins to increase (pressures above atmospheric) and the same sealed system should draw into a vacuum as the system cools down.

    So, why is smoke no longer a reliable companion in the quest to detect EVAP system leaks in this era? Smoke, being a hydrocarbon (an HC), is very similar to gasoline, and with that, gasoline can absorb the smoke being introduced to the system before the smoke has a chance to escape from a leak point. This can make leak detection by smoke nearly impossible at times. Even with a UV-dye additive and black light.

    However, with the Digital Dual Smoke Machine from Master Cool, a very efficient and effective testing technique can make light work of even the smallest of leaks. Of course, this smoke machine still functions as such but also incorporates an on-board 12v DC powered pump with system pressure as low as 0.5 psi. This makes it very safe for EVAP system testing on virtually any OBD2 certified vehicle. The tool is also capable of up to 20 psi for testing of systems such as pressurized induction.

    The Master Cool Digital Dual Smoke Machine incorporates an internal pressure transducer in parallel with the pressure circuit. The digital line graph display allows tool to indicate pressure loss over time so even the smallest of leaks are highly visible.

    Want to know more, Join Motor Age Technical Editor, Brandon Steckler in this diagnostic video as he leverages the Master Cool Digital Dual Smoke Machine to demonstrate its efficiency in this episode of The Trainer!

     

     

    There's lots more from Motor Age! Check out our Motor Age video library

    Receive your FREE SUBSCRIPTION to Motor Age!

    Each issue is packed with in-depth technical articles from experts, brief tech tips and repair strategies, TSBs, and much, much more!

    DID YOU KNOW? Motor Age offers a library of ASE Certification training materials. Motor Age Training's books, practice tests and video resources are edited by ASE Master Technicians with years of experience in repair processes. Each product is designed to help you prepare for and pass your ASE certification exam – GUARANTEED. CLICK HERE TO FIND OUT MORE:

    FOLLOW US ON FACEBOOK

    VISIT OUR WEBSITE FOR EVERYTHING AUTOMOTIVE

     @@@@@@@@@@@@@@@@@

    Due to factors beyond the control of Endeavor Business Media, it cannot guarantee against unauthorized modifications of this information or improper use of this information. Endeavor Business Media assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. Endeavor Business Media recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of Endeavor Business Media, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage, or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not Endeavor Business Media.

    The tool and/or equipment featured in this video was supplied by the manufacturer and may or may not be retained by the reviewer at no cost.

    About the Author

    Brandon Steckler | Technical Editor | Motor Age

    Brandon began his career in Northampton County Community College in Bethlehem, Pennsylvania, where he was a student of GM’s Automotive Service Educational program. In 2001, he graduated top of his class and earned the GM Leadership award for his efforts. He later began working as a technician at a Saturn dealership in Reading, Pennsylvania, where he quickly attained Master Technician status. He later transitioned to working with Hondas, where he aggressively worked to attain another Master Technician status.

    Always having a passion for a full understanding of system/component functionality, he rapidly earned a reputation for deciphering strange failures at an efficient pace and became known as an information specialist among the staff and peers at the dealership. In search of new challenges, he transitioned away from the dealership and to the independent world, where he specialized in diagnostics and driveability. 

    Today, he is an instructor with both Carquest Technical Institute and Worldpac Training Institute. Along with beta testing for Automotive Test Solutions, he develops curriculum/submits case studies for educational purposes. Through Steckler Automotive Technical Services, LLC., Brandon also provides telephone and live technical support, as well as private training, for technicians all across the world.

    Brandon holds ASE certifications A1-A9 as well as C1 (Service Consultant). He is certified as an Advanced Level Specialist in L1 (Advanced Engine Performance), L2 (Advanced Diesel Engine Performance), L3 (Hybrid/EV Specialist), L4 (ADAS) and xEV-Level 2 (Technician electrical safety).

    He contributes weekly to Facebook automotive chat groups, has authored several books and classes, and truly enjoys traveling across the globe to help other technicians attain a level of understanding that will serve them well throughout their careers.  

    Email