Fleet Management News & Business Info | Commercial Carrier Journal
Issue link: http://read.uberflip.com/i/858523
32 commercial carrier journal | august 2017 Tips for maintaining a smoother ride BY JASON CANNON A n air spring suspension provides a better ride quality than its steel spring counterpart, but it isn't quite as bulletproof when it comes to wear and tear. Air springs should be inspected at every preventive main- tenance interval or when a system air leak is detected. ey need to be checked visually for any splits, cuts and deformities in the flex member, and for cracks or missing portions of the lower piston. Steve Berry, global field service director for Hendrickson, said any "checking" – small cracks formed when molecules of ozone gas react with rubber compounds – can be dismissed as a natural occurrence on the flex member's rubber face. When ozone attacks the rubber, it frequently causes discol- oration and small surface cracks – a condition that's especially prevalent in hot urban environments. Ozone cracking is different from an abrasion, which typ- ically would be isolated to a particular area – as opposed to consistent along the spring's circumference – and should be addressed immediately, said Mark Hilburger, Firestone Indus- trial Products marketing director. Road grime Because of their position under the truck, air springs can accumulate seasons of road grime and sludge. While there are no specific guidelines for routine washing, a good practice is to wash the entire suspension aer winter, Berry said. "is will remove the caustic chemicals used for snow removal from all the components, preventing premature corrosion damage," he said. "If an air spring flex member is ex- posed to petroleum-based products, the affected area should be thoroughly cleaned with a mild detergent. is will prevent soening or rotting of the rubber." When washing the rubber, it's best to use a mix of soap and water, avoiding organic solvents, pressure washing or steam, all of which could cause damage, Hilburger said. "Wiping the flex member clean with this solution and clearing any debris from between the flex member and piston will help prolong the life," said David Brinkman, Stemco's air spring segment business leader. Proper inflation Among the keys in getting the most life from your air spring is keeping them inflated. "Drivers sometimes dump the air out of the system to get under certain dock conditions," Hilburger said. "When they drive away [before allowing the system to fully reinflate], everything is now compressed on itself, depending on parking conditions of the truck or trailer. at causes issues – being pinched on the suspension." Bad shocks also can shorten the life of air springs, which rely on the shock to limit their range of travel. Shock absorb- ers should be checked for signs of leaking hydraulic fluid, broken end connections, worn bushings or cylinders and overextension. "Periodically, check the suspension for proper ride height," Brinkman said, adding that the height control valve should be inspected to see that it is functioning properly and should be cleaned or replaced as needed. "e dimension should be maintained plus or minus a quarter of an inch to protect the air springs and shocks from overextension or frequent bottoming out of the suspension," he said. Replacement likely Steel springs under proper conditions can last the life of the truck, but air springs likely will need to be replaced at least once on extended ownership cycles depending on the appli- cation. An air spring's life can be determined by measuring the pressure needed to achieve design height. According to ContiTech, when installing a new air spring, the pressure gauge rating when the vehicle is idle should be noted. e rating should be checked periodically. When the pressure rating increases by 15 percent to achieve design height when the truck is idle, the air spring should be replaced, ContiTech said. in focus: AIR SPRING CARE Air springs should be inspected visually for splits, cuts, defor- mities and cracks at every preventive maintenance interval or when a system air leak is detected.