23.7.
Tyre Maintenance
During removing, dismantling, assembly, and fitting of wheels and tyres reasonable care must be taken to reduce accidents, injury, and damage. These recommended precautions if followed when servicing wheels and tyres can considerably reduce the incorrect practices.
23.7.1.
Removing the Wheel and Tyre
(a) The vehicle should be jacked on a flat hard surface and not on soft or uneven ground.
(b) The wheels are checked for damage and the parking brake is applied and ensured effective.
(c) Axle-stands with a jacked up axle should always be used, (rf) Personnel should not lean against a jacked up vehicle.
(e) The valve core must be removed completely to deflate the tyre before removing the
wheel from the vehicle or the tyre from the wheel. if) The outer clamping nuts should not be loosened or unscrewed on divided wheel rims. (g) Care must be taken not to distort flanges and lock-rings during dismounting of tyres.
23.7.2.
Examination and Preparation of the Cover and Rim
(a) The parts of the rim that come into contact with the tyre bead, should not distort or damage in anyway.
(b) Any accumulation of rust on the flange gutter and rim base is removed. These surfaces are cleaned with a wire brush and emery cloth if necessary, and then repainted with epoxy-resin paint if necessary.
(c) The tyre case is examined inside and outside for any damage or manufacturing defects.
(d) The cover beads are wiped with a clean dry rag and then the cover beads, flange, and rim are lubricated.
(e) The sizes of wheel, tyre and valve for tubeless, and the wheel, tyre, flap (if fitted) and valve for tubed assemblies are checked for compatibility.
(/) The stud holes are checked for any damage or elongation. Cracked rims and stud-atÂtachment naves with wheels should not be used.
(g) The split flanges and lock-rings used with truck wheels and rims should not be distorted and should be of the correct size and type.
23.7.3.
Reassembly and Inflation of Wheel and Tyres
(a) Whenever a tubeless tyre is renewed, the complete valve should also be renewed.
(b) The tyre-and-wheel assembly is placed flat on the ground so that the cover takes up its correct position on the rim to obtain a good airtight seal.
(c) Initially the assembly is inflated with the removed valve core to a pressure of 100 kPa. id) If the tyre does not inflate, the air line is kept connected and the assembly is rolled
along the ground. Once the tyre beads have seated, the air line is disconnected and the valve core is inserted. (e) A moist or contaminated air supply should not to be used.
if) The fitting line at the tyre beads should be concentric with the wheel flange, to avoid unnecessary lift or run out.
(g) The tyre is placed in a safety cage and the air line between the valve and the person inflating the tyre should be long enough to prevent any damage from flying components in the event of a tyre or wheel burst.
(h) If no tyre guard is available, then the assembly should be leaned against a wall, with the lock-ring/loose flange facing the wall.
ii) The correct pressure for the size and application is to be established before inflating,
and not to be over-inflated. (J) Standing in front of or leaning over the tyre during inflation must be avoided. (k) All pressure gauges and air-metering devices must be checked against a master
pressure gauge.
(I) It is essential that all wheel nuts are fully tightened following the correct sequence, alternating opposite sides of the wheel. (m) Wheel nuts must not be under-tighten or over-tighten and, if a power tool is used, the correct tightening torque is to be checked.
