Truck Tyre Maintenance

The must important factor in caring for and maintaining tyres is the right choice of tyre for a particular operation. Having thus ensured that maximum tyre life will be achieved, certain precautions can be taken to lessen the chances of premature removal.

Storage

• Do not expose products to heat and ozone sources
• Protect from over-exposure to sunlight, rain and strong wind.
• Prevent rubber deterioration from contact with grease, petrol and other volatile substances.
• When storing tyre fitted with rims, reduce inflation pressure.
• Constantly turn stock over.
• Keep the inside of the tyre free from water or moisture.
• Always store flaps and inner tubes on shelves, never suspended.

Tyre selection and replacement

The original tyres which were fitted to the vehicle are ideal for The speed and maximum axle weight of that vehicle.

The load index should match that of the original tyres and the speed symbol be legally acceptable when replacement tyres are being selected.

Where there is no service description available, a tyre specialist must be consulted.

• Regular checks on tyre tread depths are advisable. Generally speaking, The shallower the tread, the greater the risk of skidding in wet weather.
• Tyres should preferably be replaced before 1 .6mm of tread remains. There are indicators to this effect which are situated in the groove base. They are known as TWI (tread wear indicators).
• Only those used tyres with a traceable history should be fitted. Tyre specialists/manufacturers are the experts to advise on tyre replacement.

Inflation pressure

A vital factor in road safety awareness is correct inflation pressure.

• Inflate tyres to the correct pressure for a particular use and maintain this pressure.
• The long life of a tyre can be threatened by over-heating caused by under-inflation. When a tyre overheats, road-holding ability is impaired, it wears irregularly and could even break up completely, due to internal damage.
• To over-inflate a tyre is just as ill-advised. Impact damage becomes a greater possibility and, in the worst conditions, The rim could fail or the tyre could burst.

Possible results of incorrect inflation pressure are:

• Increased fuel consumption.
• Shorter life-span of tyre.
• Uneven tread wear.
• Increased possibility of blow-outs.
• Increased tendencies to split or crack.
• Decreased performance and impaired vehicle handling.

Important points to remember:

• Check inflation pressure of all tyres, including the spare, at least once a week. Tyres must be cold when the pressure is checked as warm tyres have built up to a higher pressure.
• Bleed tyres only when cold.
• Adhere to manufacturer's recommendations with regard to cold inflation pressures. Keep in mind the tyre type and the use for which it is intended.
• Valve caps must always seal perfectly.
• Make sure that these are metal type and not plastic.

Use and maintenance

• Vehicle load, environmental conditions and condition of the road surface are factors that must influence driving behavior.
• Suitable load distribution will minimise the effects of either total or localised overload.
• Tyre balance must be checked regularly.
• Wheel nuts should be checked for tightness 100 km or three hours of use after tyre fitting, and regularly thereafter.
• Proper pressure gauge use is important; check that it is correctly calibrated.
• Vehicle tyre examination should include attention to:
  • tread; uneven wear, cuts, abnormalities and foreign objects such as nails and small stones.
  • sidewalls; cracks, cuts, abrasions, impact damage and localised deformities.
  • bead/rim flange area; rim damage, chafing and misfitment.
  • duals; foreign objects, abrasions, deformities and cracks.
• Duals must first be deflated before removing foreign objects lodged between them.
• Tread must be cleared of any trapped objects and oil or grease contamination cleaned at once.
• Where damage has occurred, the tyre must be taken to a specialist.
• As internal damage is not visible, it must be remembered that this can be caused by a variety of factors and that a specialist must be consulted if there is any suspicion of it. Bad road surfaces, pot-hole or kerb collision are all possible threats to tyre life span.
• Any unusual tendencies during normal driving, such as pulling to one side, should receive immediate attention.
• When a tyre is punctured, it must be changed immediately because structural deterioration will result from under-inflation.
• Secondary damage is possible after a puncture. The tyre must therefore always be removed from the wheel and checked.
• Liquid sealants and other products used for punctures are not recommended as they make investigation of damage difficult.
• A tyre specialist is always the best solution to tyre repair problems, as full responsibility is then passed to him.
• Suitable tyre rotation is advisable after repairs.

Sundry notes

The aging of tyres, whether or not they have been used regularly, is a fact of life. Evidence of this can be seen as cracks in the tread sidewall rubber and also carcass deformation. A tyre specialist can only recommend the safe use of these tyres after a thorough check.

A specialist should assess tyre condition at least every year, irrespective of distances covered or residual tread depth. He will advise on the necessity of replacement.

Some vehicles which are of necessity parked for long periods of time are cranes and trailers, among others. The wheels of these vehicles need to be jacked up as the tyres age and crack more quickly than those which are run more frequently.