Michelin has issued advice relating to tyre health for operators that are taking, or have taken, coaches or buses out of use for an extended period as a result of the coronavirus COVID-19 pandemic. Following it will ensure that the lifespans of those vehicles’ tyres will not be compromised.
The guidance from Michelin covers steps that should be taken before and during extended periods out of use, and before the vehicles concerned return to service. It has been compiled by Rob Blurton, Michelin’s most senior Technical Field Engineer in the UK.
He says: “No tyre is designed to carry the weight of a parked vehicle indefinitely. It’s essential that operators follow guidance to ensure that their vehicles can be quickly returned to service when conditions allow, and without the need to replace tyres unnecessarily.”
Preparing tyres for lay-up
Before a vehicle is parked for an extended period, its tyres should be checked for visible damage and abnormal wear, Rob says.
Cold tyre inflation pressures should also be measured. If that check reveals underinflation by up to 14psi, a check should be made for any visible cause. When nothing is found, the tyre should be inflated to the recommended pressure.
If the tyre is underinflated by more than 14psi, it should be demounted and its interior should be inspected for signs of internal damage, such as mottling or creasing. On drive axles, the twin assembly should also be demounted and inspected. Valve caps should be checked to ensure they are present.
Steps during extended parking
While there is yet no sign of how long restrictions on movements will be in place, it is possible that some vehicles used for home-to-school transport could be idle until they are reactivated in time for the new academic year in September.
Michelin advises that where vehicles are parked long-term, they should be driven around the operator’s yard every four months. If space is at a premium and that is not possible, the tyres should be rotated by a quarter turn.
Before moving a vehicle under these circumstances, tyres should be checked visually for signs of underinflation. If a tyre is deemed to require attention, the guidance above should be followed.
Before re-entering service
Before any coach or bus is returned to use, its cold tyre inflation pressures should be checked and if necessary adjusted to satisfy the tyre manufacturer’s guidance.
Commenting on the tyre advice issued by Michelin, Rob says: “The notion of parking coaches and buses for extended periods is unfamiliar to most operators, with the possible exception of heritage vehicles and open-top buses during the colder months.
“However, these are important steps that will help to protect the condition of the tyres and ensure that vehicles remain ready to go back to work.”
Further advice can be found on Michelin’s website.