Wheels & tires: Procedures to using a Tire Pressure Gauge

Wheel & Tires:

Using a tire pressure gauge

Part 1. Preparation and safety

Objective

• Use a tire pressure gauge and interpret the readings correctly.

Personal safety
Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:

• Work clothing - such as coveralls and steel-capped footwear
• Eye protection - such as safety glasses and face masks
• Ear protection - such as earmuffs and earplugs
• Hand protection – such as rubber gloves and barrier cream
• Respiratory equipment – such as face masks and valved respirators

Wheels & Tires : Wheel alignment fundamentals

Wheels & Tires:

Basic principles of wheel alignment

All wheels of a vehicle must be correctly positioned, with the vehicle and with each other, for the vehicle to drive and steer properly.
A driver should not need to keep manipulating the steering wheel to maintain the vehicle in a straight-ahead position on straight, level roads.
Similarly, little effort should be needed to turn the vehicle into curves, or to let it return to the straight-ahead position, when the curve has been negotiated.
Wheels are installed on the suspension units at certain angles, to provide for these factors. These angles, taken together, are called wheel alignment.
The factors that affect wheel alignment are

Wheels & Tires : Tire construction

Wheels & Tires:

Tire construction

A tire provides a cushion between the vehicle and the road, to reduce the transmission of road shocks.
The air in the tire supports the vehicle’s mass, and the tread provides frictional contact with the road surface, so the vehicle can maneuver for normal use.
Radial ply tires are usually manufactured in stages.
The casing is initially formed by laying the rubber inner liner, and the first layer of textile ply cords, around a flat drum mold.

Wheels & Tires : Tire types & characteristics

Wheels & Tires

Tires

The tire provides a cushion between the vehicle and the road to reduce the transmission of road shocks. It also provides friction to allow the vehicle perform its normal operations.
Modern tyres are manufactured from a range of materials. The rubber is mainly synthetic.
Two types of tire construction are common - cross-ply and radial.
Most passenger cars now use radial tires, as do most 4-wheel-drives and heavy vehicles.
Tube tires require an inner tube to seal the air inside the tire.
Tubeless tires eliminate the inner tube by making the complete wheel and tire assembly air-tight.
A special, air-tight valve assembly is needed. This can be a tight fit into the rim, or it can be held with a nut and sealing washers.

Wheels & Tires: Wheel types & sizes

 Wheels & Tires:

Wheels

Wheels must be strong enough to support the vehicle, and withstand the forces caused by normal operation. At the same time, they must be as light as possible, to help keep unsprung weight to a minimum.
Wheels can be made from pressed steel, in 2 sections - the flange or disc that is drilled for the wheel fasteners, and the rim.