Brake Defect Causes Recall Of Over 30,000 Semi Trailers

Published on July 29th, 2016 by Steve Wilcox

On June 8^th, Bendix Commercial Vehicle Systems notified a recall to the National Highway Traffic Administration. The company is recalling close to 195,000 Bendix spring brake valves due to a defect.

The recall claims that, “Certain SR-5 Trailer spring brake valve bodies were machined without a radius (Internal check valve seat)” which causes a delay of application of spring brakes while parking.

“During transition to a new valve body supplier, a radius dimension was inadvertently omitted from a
revised engineering drawing.”

According the recall,

“Under certain conditions (primarily off-highway or in trailer yards) there can be a delay in the application of the spring brakes to park the trailer after the operator pulls the dash valve button. This slow to park condition could lead to trailer roll away after decoupling.”

The symptoms of affected vehicles were described in the recall,

If the internal leakage develops in the SR-5, a leak can be heard or observed. This leakage will continue until the trailer reservoirs & spring brake chambers are depleted of air pressure. If coupled to a tractor, a leak may be heard from the exhaust of the dash valve (Bendix® MV-3TM dash control valve) or from the tractor protection valve. If uncoupled, a leak may be heard at the supply (red) gladhand on the trailer. Additionally, if uncoupled & the internal leakage is present, there will be a loss of air pressure in the trailer reservoir, resulting in the eventual parking of the brakes. ‘Slow to apply’ condition can range from 30 seconds to several minutes depending on the severity of the leak
Lastly, empty reservoir may impact the function of other air powered features on the trailer, such as slider locking pins, if so equipped.

Trailer manufacturers have been recalling trailers due to this issue. So far, 10 companies have issued recalls, and in total, more than 30,000 trailers have been recalled. Specifically, SR-5 trailer spring brakes manufactured from January 2^nd, 2014 to March 4^th, 2016 are affected.

The following trailers have been affected: