HEATING AND AC – CUSTOMER CARE

HEATING AND AC – CUSTOMER CARE

Regular Checks Regular servicing is vital for a customer’s safety. Carry out checks at all services and report your findings to the customer. Advise customers if anything will need attention before the next scheduled service interval.

Vehicle Condition Respect your customer’s vehicle and take precautions to keep it clean. Repairing or checking some systems, is likely to involve you working under the vehicle, and then sitting in the driver’s seat. Use seat covers and ensure the steering wheel is clean when you have finished.

Communication Some AC systems, at first view, may appear complex. Help your customers by showing them how the different functions are operated. Some customers may think they have a fault with their system, when in fact it is operator error! Some systems for example, run the demist option automatically for a few seconds after the engine first starts. The controls do not make any difference during this time and thus it may appear that there is a fault.

Recommendations During the winter period, it is possible that the AC system will not be used. Recommend to your customers that it is beneficial to run the system at least once a month. This ensures that the compressor stays lubricated and the refrigerant is distributed throughout the system. Many systems cause the AC to be switched on automatically when the front

screen ‘demist’ option is selected.

Summary A customer who is kept informed and treated with respect will return and keep you in a job! Explain things to a customer when asked – it will be appreciated.

CHASSIS SYSTEMS

SUSPENSION REASONS FOR SUSPENSION

Introduction The suspension system is the link between the vehicle body and the wheels. Its purpose is to:

Suspension plays a key

Locate the wheels whilst allowing them to move up role and down, and steer

Maintain the wheels in contact with the road and minimise road noise

Distribute the weight of the vehicle to the wheels Reduce vehicle weight as much as possible - in

particular the unsprung mass Resist the effects of steering, braking and

acceleration Work in conjunction with the tyres and seat springs

to give acceptable ride comfort.

Compromise The previous list is difficult to achieve completely, so some sort of compromise has to be reached. Because of this, many different methods have been tried, and many are still in use. Keep these requirements in mind, and it will help you to understand why some systems are constructed in different ways.

Sprung and Unsprung Mass ฀฀฀Unsprung mass is usually the mass of the suspension component, the wheels and the springs. However only 50% of the spring mass and the moving suspension arms are included. This is because they form part of the link between the sprung and unsprung masses. It is beneficial to have the unsprung mass as small as possible in comparison with the sprung mass (main vehicle mass). This is so that when the vehicle hits a bump the movement of the suspension will have only a small effect on the main part of the vehicle. The overall result is therefore improved ride comfort.

Further In Suspension A vehicle needs a suspension system to cushion and damp out road shocks. This provides comfort to the passengers and prevents damage to the load and vehicle components. A spring between

Suspension system

the wheel and the vehicle body allows the wheel to follow the road surface. The tyre plays an important role in absorbing small road shocks. It is often described as the primary form of suspension. The vehicle body is supported by springs located between the body and the wheel axles. Together with the damper, these components are referred to as the suspension system.

Effect of Suspension ฀฀฀As a wheel hits a bump in the road, it is moved upwards with quite some force. An unsprung wheel is affected only by gravity, which will try to return the wheel to the road surface. However, most of the energy will be transferred to the body. When a spring is used between the wheel and the vehicle body, most of the energy in the bouncing wheel is stored in the spring and not passed to the vehicle body. The vehicle body will only moves upwards through a very small distance compared to the movement of the wheel.

Springs These parts of the suspension system take up the movement or shock from the road. The energy of the movement is stored in the spring.

Coil spring

The actual spring itself can be in many different forms, ranging from a steel coil to a pressurised chamber of nitrogen. Soft springs provide the best Leaf spring comfort, but stiff springs can be better for high performance. Vehicle springs and suspension therefore are made to provide a compromise

Gas spring

between good handling and comfort.

Torsion bar spring