{"id":11471,"date":"2021-06-12T11:11:58","date_gmt":"2021-06-12T09:11:58","guid":{"rendered":"https:\/\/advancedfleetmanagementconsulting.com\/eng\/?p=11471"},"modified":"2021-06-12T11:11:58","modified_gmt":"2021-06-12T09:11:58","slug":"air-brake-system-leaks","status":"publish","type":"post","link":"https:\/\/advancedfleetmanagementconsulting.com\/eng\/2021\/06\/12\/air-brake-system-leaks\/","title":{"rendered":"Getting to the bottom of air brake system leaks"},"content":{"rendered":"

Faulty fittings, unsuitable seals, and corrosion can make air brake system leaks a challenge for fleets.<\/span><\/p>\n

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Brake systems continue to represent the top reason for roadside inspection violations in the U.S. In fact, according to data from the Commercial Vehicle Safety Alliance (CVSA) International Roadcheck that took place in September 2020, brake system failures accounted for 25 percent of all vehicle-related out-of-service violations.<\/span><\/p>\n

There is just no messing around when it comes to brake systems \u2014 especially air brake systems. Unfortunately, there are a lot of opportunities for problems to emerge. Technicians must remain on their toes, particularly with respect to system leaks.<\/span><\/p>\n

Redline Detection is a manufacturer of diagnostic leak detection equipment. According to Mark Hawkins, head of technical products for Redline Detection, air brake leaks are becoming an even bigger issue for some fleets. That is why the Technology & Maintenance Council (TMC) has set up a task force to help address the issue.<\/span><\/p>\n

\u201cOne of the big topics now is that some fleets have reported taking delivery of new vehicles that already have air leaks,\u201d Hawkins said. \u201cSometimes it is a matter of things being assembled incorrectly, or maybe some components were not high-quality enough. Sometimes it is something simple like hoses not being cut correctly to make the perfect seal. That is the nature of the beast. Heavy duty trucks have always had leaks like this.\u201d<\/span><\/p>\n

According to Chuck Brodie, field service team leader for ZF Commercial Vehicle North America, air brake system leaks are generally not a problem \u2014 except for one potential issue.<\/span><\/p>\n

\u201cWe don\u2019t typically see any leaks at our valves unless there is a fitting issue,\u201d Brodie pointed out. ZF is a technology company that supplies systems for cars, commercial vehicles, and industrial technology. ZF acquired WABCO Holdings in May 2020.<\/span><\/p>\n

To Brodie\u2019s point regarding fitting issues, technicians should always ensure that fittings are installed correctly and that air lines are carefully routed to avoid damage. Additionally, it is important to use care when diagnosing a leaking valve.<\/span><\/p>\n

\u201cAir coming out of the exhaust port of a valve doesn\u2019t always indicate an issue with the valve,\u201d Brodie said. \u201cThe air brake system leak could be originating from other places in the system such as the brake chamber.\u201d<\/span><\/p>\n

Hawkins said some of today\u2019s heavy duty trucks have characteristics that make them more susceptible to a leak. Historically, main lines were heavy duty copper with threaded connections. Leaks rarely emerged unless rub-through occurred.<\/span><\/p>\n

\u201cThen things went to rubber to the brakes on the axles,\u201d Hawkins said. \u201cFleets never really had a problem because everything had a good heavy duty connection and everything was still threaded between parts.\u201d<\/span><\/p>\n

Today, things have started to change. For speed of manufacturing, some OEs have gone to plastic with quick-coupler fittings. There are also large bundles of air lines because air is being supplied to not only the brakes, but also to the suspension and the cab, among other areas of the vehicle.<\/span><\/p>\n

\u201cThings just aren\u2019t as robust as they used to be,\u201d Hawkins related.<\/span><\/p>\n

Richard Nagel, director of marketing and customer solutions for air supply and drivetrain at Bendix Commercial Vehicle Systems, said that whether a push-to-connect fitting is made of brass or nylon, it doesn\u2019t always create the perfect seal. That can lead to small air leaks depending on the quality of the cut in the line.<\/span><\/p>\n

\u201cThese fittings can also be highly susceptible to chemicals and temperature fluctuations,\u201d Nagel pointed out.<\/span><\/p>\n

Bendix is a developer of active safety technologies, air brake charging, and control systems for medium and heavy duty vehicles and trailers.<\/span><\/p>\n

Corrosion is a major cause of leaks<\/span><\/h3>\n

Roadway surface treatments have also become a major cause for air brake system leaks. To help mitigate this issue, fleets should have strong inspection processes in place, as well as quality components that are designed to be up to the task.<\/span><\/p>\n

\u201cSome of the new de-icing treatments that are being used more regularly, like magnesium chloride, are causing a lot of corrosion issues,\u201d Nagel said.<\/span><\/p>\n

Technicians not only need a thorough winter-prep regimen for trucks and trailers, but also a post-winter regimen to look for any damage that may have emerged over the winter months.<\/span><\/p>\n

The transition from winter to spring and into summer creates other potential corrosion-related issues for fleets. Nagel said the contrast of cold temperatures and heat coming off of the engine can spell trouble in the following ways:<\/span><\/p>\n