CHARLOTTE, N.C. — Smithereens. That is precisely where you could blow your face to if you make a mistake working on a double-clamp banded spring brake.

Good thing they’re not on the market any more, right? Wrong.

They’re back. And that fact has inspired one of the continent’s high-end brake manufacturers to issue a warning: Work on double-clamp banded spring brakes at your extreme peril.

According to Wayne Seaman of MGM Brakes in Charlotte, N.C., some aftermarket brake manufacturers — mainly overseas exporters from Asia who think they can make a buck producing cheaper actuators — have re-introduced the double-clamp versions to the North American market. And in the hands of an inexperience technician, these babies are dangerous, says Seaman.

Time was, the spring and service chambers of actuators were held together with two clamps. Seaman, who has been in the business more than 30 years, says sometimes technicians would try to work on the spring side of the unit without first “caging” the spring, the spring would let go and serious injury and damage would result.

In 1987, MGM re-designed the actuators with only one clamp, so the spring side was inaccessible. By the early ’90s, the entire industry had embraced this design. Seaman says injuries due to inexperience essentially disappeared.

Now that they’re back, he says, there’s a whole generation of technicians who have no experience with the obsolete units. “Especially at risk,” says Seaman, “are those workers least experienced in the industry. Many in the service and maintenance end of the industry have not seen, let alone serviced, a double-clamp banded spring brake.

“Younger workers are not likely to have been trained in the special safety procedures required to cage the brake before servicing the spring parking side of the units,” he says.

For more information go to www.mgmbrakes.com and click on Tech Tips: Industry Safety Reminder. Or go to TodaysTrucking.com’s exclusive “Brake Systems” category in our Decision Centers for everything you need to know about brakes (link below).