The use of Air-Seal in dumper tyres to assist in long term pressure maintenance

26th April 2018

The following piece was published in Tyre Press news and explains the issues experienced with underinflated tyres in one particular piece of plant.

Having supplied 35,000 dumper truck tyres and wheels in the UK last year – 100 per cent of all dumper tyres for new trucks in our market – STARCO knows a thing or two about looking after these products. It’s therefore worth taking note when the company warns of the potential danger and additional cost of operating at low air pressure.

“Apart from accidental damage, the failure to maintain proper tyre pressure is the most important reason for premature tyre failure,” comments Phil Robbins, sales support engineer at STARCO. Robbins, who in a variety of previous technical roles at Michelin has gained nearly 30 years of tyre experience, explains in more detail:

“Tubeless tyres and valves are not completely airtight. They lose air naturally, as the air molecules pass slowly through the body of the tyre and valve, gradually reducing the air pressure. When running underinflated, the sidewall of the tyre is over flexing causing undue strain on the casing of the tyre.”

Consequences of underinflated tyres

Air pressure plays a very important role in vehicle stability, especially when working on gradients. Lower air pressure reduces the tyre’s sidewall stiffness, which in turn reduces the gradient specified as safe by the dumper manufacturer’s specifications.

“Due to the type of work that site dumpers do, empty/full/empty-cycles, a site dumper that is empty will appear to be okay, because the tyres will generally have more than enough pressure to support the empty weight of the vehicle. However, as soon as the skip is filled the tyre will be underinflated for the load,” explains Robbins.

This underinflated running can have damaging consequences: The tyre’s sidewall over-flexes, causing undue strain on the casing. In addition, the over-flexing causes the bead to rock over the rim flange/horn, wearing the bead, and can allow foreign matter to enter into the interface between tyre and wheel.

“A pressure maintenance schedule is vital to achieve a full tyre service life,” advises Robbins.

Maintenance tips

• Always check tyre pressures at least once a month.
• Always check the tyre pressure before use when the tyre is cold (un-run).
• Never reduce the pressure of a warm tyre.
• Always fit sealing valve caps after inflation and replace if damaged.
• Always inflate the tyres to the pressures recommended by the vehicle manufacturer.

Back