Part 1. Preparation and safety
Objective
- Check and adjust tire pressures to correct levels.
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
If you are not certain what is appropriate or required, ask your supervisor.
Safety check
- If you check the tire pressures after the vehicle has been driven a long distance and the tires are hot, DO NOT RELEASE this excess pressure. If you bleed the tire down to the manufacturer's recommendation, it will be under-inflated when the tire is cold or at normal operating temperature. This could cause the tire sidewall to fail.
- Never inflate a tire above the manufacturers recommended maximum pressure.
- Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.
Points to note
- Tires get hotter as they are being driven. Driving on under-inflated tires can cause serious damage to the tires. The sidewalls are subjected to excessive flexing that can generate a great deal of internal heat.
- Check the owner's manual or the tire decal usually located on the driver's side door jam for correct pressures.
- The tire pressures should be checked when the tires are cold. On average, the pressure in a tire will increase by about 12.5 kPa for each 2°C (1 pound per square inch (psi) for each 10°F) the tire is above its normal operating temperature.
Part 2: Step-by-step instruction
- Prepare the vehicle and equipment
Park the vehicle so you can reach all four tires with the air hose. Check the recommended pressures in the owner’s manual, or on the tire decal usually located on the driver’s side door, or surrounding location.
- Check the tire sidewall markings
Check the sidewall markings on the tire for the maximum operating pressure. At the same time check the tire specifications and maximum load carrying capacity. These details can normally be found on the driver’s side of the vehicle, on a decal near the door pillar. If the tire markings do not meet the specifications of the vehicle, tell your supervisor and ask for their direction. This can have a serious effect on the performance of the tires and the vehicle.
- Check and adjust pressure
Check the pressure when the tires are cold. Remove the cap from the tire valve on the first tire. Use a reliable tire gauge to check the air pressure in the tire. A pocket type pencil gauge is ideal for this purpose. If there is a gauge attached to the air filler this is less likely to be accurate as it is more vulnerable to damage. If you need to add air, use short bursts with the air hose so you don’t over inflate the tire. Re-check the tire pressure after filling it and replace the cap on the tire valve. Repeat the process for the other tires.
Source: CDX Global
