September 13, 2017
After the recent natural disasters in Texas and Florida, Bendix Commercial Vehicle Systems has released the following insights for inspecting and (where possible) reconditioning air brake and wheel-end components that have been submerged in flood waters.
When checking a submerged tractor, “at the top of the list is the question of whether the floodwater was salt water,” says Jim Szudy, Bendix engineering manager for advanced systems engineering. “If the answer is yes, then you should immediately begin replacing parts.
“Pneumatic air brake valves that have been submerged have likely lost their lubrication, for example. Couple that with the extremely corrosive nature of salt water, and these valves would be at much higher risk for sudden and premature malfunction. Any brake system valve that’s been submerged in sea water should be replaced, along with air compressors, air reservoirs, antilock brake system (ABS) relay modulators, and brake actuators.”
Bendix says salt water also heightens the possibility of corrosion at the wheel-ends, leading to increased chances of rust-jacking and damage to other components. Again, Bendix recommends complete replacement to prevent future failure.
If a vehicle was in a coastal area, and it’s not clear whether the water submergence was by fresh water or salt water, it’s best to play things safe and follow the above guidelines. Additionally, during the replacement of any pneumatic system components that have been subjected to flood conditions, all contaminated air hoses should be disconnected, flushed with clean water, and blown out with air pressure to remove contaminants, the company says.
When it is certain that a vehicle or trailer was submerged in fresh water, power wash the vehicle and trailer, including the foundation brakes, to assist in determining the condition of components. Then take the following steps to properly check the air brake control systems:
The charging system
“Unfortunately, once water or contamination has entered into any of the air brake components – through the exhaust valves, for instance – it’s not possible to completely clear the system without total disassembly,” Szudy says. “Given the importance of a fully functioning system and clean air, it’s necessary to replace all pneumatic air brake components if you find signs of moisture or other contamination, just as you would in the case of salt water submersion.”
If no evidence of water or contamination is found, Bendix says to thoroughly test the air brake system and ABS before returning the vehicle or trailer to service. Also, where the ABS is concerned, the action of floodwaters and power washing may move the ABS wheel speed sensors from their normal position. By hand, push the wheel speed sensors back into contact with the exciter ring, and normal wheel bearing play will adjust the sensor position when the wheel turns.
Bendix recommends retesting – including diagnostic checks of electronic systems such as ABS, full stability (ESP/ESC), collision mitigation systems, and Automatic Traction Control (ATC) – 30 days after the vehicle or trailer has been returned to service.
“We’ve got resources available 24/7 to help fleets and owner-operators with questions, including 1-800-AIR-BRAKE, our Service Engineering team, and our library of Service Data Sheets and Technical Bulletins,” Szudy says. “And keep in mind that other vehicle systems may be impacted by flooding as well, so make sure you’re following all the appropriate vehicle and system manufacturer inspection guidelines.”