 State TWO ways in which interior lights are switched on.

 State TWO ways in which interior lights are switched on.

 Look back over the previous section and write out a list of the key bullet points here:

TOOLS AND EQUIPMENT

Introduction Components will usually be removed, inspected and repaired or replaced when a defect has been diagnosed. Other components are replaced, or stripped and cleaned, at scheduled mileage or time intervals. Refer to the Routine Maintenance section for details on these items.

Recommended Procedures The descriptions provided in this section deal with the components for individual replacement, rather than as a part of other work. Always refer to a workshop manual before starting work. You will also need to look for the recommended procedure, special tools, materials, tightening sequences and torque settings. Some general and specific tools and pieces of equipment are described on the following screens.

General Toolkit General tools and equipment will be required for most tasks. As your career develops you will build a

collection of tools and equipment. Look after your tools and they will look after you!

Torque Wrench A good torque wrench is an essential piece of equipment. Many types are available but all work on a similar principle. Most

A torque

are set by adjusting a screwed cylinder, which wrench is a

useful tool

forms part of the handle. An important point to remember is that, as with any measuring tool, regular calibration is essential to ensure it remains accurate.

Air Guns ฀฀ The whole point of power tools is that they do the work so you don’t have to! Most air guns have an aluminium housing. This material is lightweight but gives long life. Air guns produce a ‘hammer’ action. Because of this, impact sockets should be used. Normal sockets can shatter under this load. It is important to remember that air tools need lubricating from time to time.

Jacks and Stands Most jacks are simple hydraulic devices. Remember to make sure the safe working load (SWL) Always use

After jacking

is not exceeded. Ensure that any faults a vehicle with equipment such as this are

stands…

reported immediately. Axle stands must always be placed under the vehicle supporting the weight – before work is carried out.

Ramps and Hoists Many ramps are available ranging from large four-post wheel-free types to smaller single-post lifts. These large items should be inspected regularly to ensure they are safe.

Transmission Jack If a complete gearbox has to be removed, it is likely to be heavy! A transmission jack has attachments that allow you to support the gearbox and lower it safely. The equipment is

hydraulically operated just like an ordinary jack. This jack will

support a

Often, the height can be set by using a foot pedal, gearbox which leaves both hands free for positioning the unit.

Bearing Puller Removing some bearings is difficult without a proper puller. For

internal bearings, the tool has small

Internal

External bearing puller

legs and feet that hook under the bearing puller bearing. A threaded section is

tightened to pull out the bearing. External pullers hook over the outside of the bearing and a screwed thread is tightened against the shaft.

Air Ratchet These tools are very useful for removing or fitting nuts and bolts. However, it is possible to over tighten if care is not taken. Air

These tools

tools can be very powerful and will trap your hands! are very

useful

Take adequate precautions at all times.

Headlamp Beam Setter Correct beam alignment is

a legal requirement; it is also necessary for efficient operation of vehicle headlights. Many

Alignment

types of beam setting equipment are available and equipment most work on the same principle. The method is the

same as using an aiming board but is more convenient and accurate due to easier working and less room required. A lens at the front collects light and a mirror reflects the beam pattern onto a small screen.

 Look back over the previous section and write out a list of the key bullet points here:

ROUTINE MAINTENANCE

Scheduled Servicing Scheduled service requirements are often quite simple but none-the-less important. Systems should be checked for correct operation. Adjustments, repairs or replacements are then made if required.

Non-Routine Work When carrying out routine maintenance, some non-routine work may be found. This should be reported to the driver or owner of the vehicle before repairs are carried out.

Worksheet Check all vehicle lights for

Indicators

operating

correct operation. This is a simple check carried out as part of all

services. However, it is a vital safety aspect. Check lights for correct operation, colour and flash rate where appropriate. Indicators should flash between

60 and 120 times per minute.

Lighting Operation It is necessary to use an assistant when checking lights – or carefully positioned mirrors! It will be necessary to switch

Headlights

the ignition on for some of the lights to operate. Remember to check instrument and interior lights.

Lighting Colours Regulations relating to different light colours vary in different parts of the world. However, most are similar and are summarised as follows:

• Headlights – white, yellow, blue/white • Indicators – amber (UK), red/amber (US) • Sidelights – white • Rear lights – red • Stoplights – red • Reverse lights – white.

Type of Light The type of light emitted is either described as a beam or diffused. Headlights and auxiliary lights emit beams. All other exterior

Spotlight

lights emit diffused, or non-focussed, light. This is to prevent other road users being dazzled.

Worksheet Check all vehicle lights for condition and

security. As well as operating correctly, vehicle lights must be secure,

clean and in good condition. Lenses should be free from cracks and damage. Reflectors should be clean and free from corrosion.

Headlights Cracks in the lens of a headlight or corrosion of the reflector, can cause a disruption to the beam emitted. In some countries, any crack Damaged makes the lights illegal. However, in the UK for headlight lens example, the lights can fail the annual MOT test for a cracked lens, but only if the beam is adversely affected. Generally, corrosion will prevent correct operation and the reflector of the light unit should be renewed.

Rear lights No white light should be emitted from the rear of a vehicle except when reversing or intending to reverse. Check carefully for cracks in Damaged rear

the lenses of all the rear lights. light lens

Summary Safety of all road users and pedestrians is essential. Reliable operation of the vehicle is also important. The

condition of all systems is therefore vital. Carry out a check at all service intervals.

 Look back over the previous section and write out a list of the key bullet points here:

LIGHTING – 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 cust omer’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.

Lighting Make sure that all the lights operate correctly when you check a customer’s vehicle. Pay attention to details such as panel lights or instrument lights. Even a simple fault, such as a blown instrument illumination bulb, is very important.

Light units Some light units can be very expensive. Headlights in particular can be damaged by flying stones when the car is moving. Some manufacturers supply protective covers that fit over the front lights. If your customer uses the vehicle in off road conditions, he or she may appreciate advice about light covers.

Headlight units can be very expensive

Adjustments A correctly adjusted headlight beam pattern will ensure that your customer’s lights will be operating to their best performance. The methods for adjusting headlight alignment are covered in the Component Inspection and Repair section.

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.

BODY ELECTRICAL AND ELECTRONIC SYSTEMS WASHERS, WIPERS AND HEATED SCREENS

Windscreen Washers and Wipers ฀฀ The requirements of the wiper system are simple. The windscreen must be clean enough to provide suitable visibility at all times. To do this the wiper system must meet the following requirements:

Efficient removal of water and snow Efficient removal of dirt Operate at temperatures from -30 to 80°C Pass the stall and snow load test Have a service life in the region of 1.5 million wipe cycles Be resistant to corrosion from acid, alkali and ozone.

Wiper Blades Wiper blades are made of a rubber compound and are held on to the screen by a spring in the wiper arm. The aerodynamic property of the wiper blades has become increasingly important. The strip on top of the rubber element is often perforated to reduce air drag. A good quality blade will have a contact width of about 0.1mm. The lip wipes the surface of the screen at an angle of about 45 degrees. The pressure of the blade on the screen is also important.

Wiper Linkages ฀฀ Most wiper linkages consist of a series or parallel mechanism. Some older types use a flexible rack and wheel boxes similar to the operating mechanism of many sunroofs. One of the main considerations for the design of a wiper linkage is the point at which the blades must reverse. This is because of the high forces on the motor and linkage at this time. If the reverse point is set so that the linkage is at its maximum force transmission angle, then the reverse action of the blades puts less strain on the system. This also ensures smoother operation.

Wiper Motors All modern wiper motors are permanent magnet types. The drive is taken via a

worm gear to increase torque and reduce speed.

Motor brushes and

Three brushes may be used to allow two-speed armature operation. The normal speed operates through two brushes placed in the usual positions opposite to each other. For a fast speed, the third brush is placed closer to the earth brush. This reduces the number of armature windings between them, which reduces resistance, hence increasing current and therefore speed.

Circuit Protection Wiper motors or the associated circuit must have some kind of short circuit protection. This is to protect the motor

Wipers frozen on

in the event of stalling, if frozen to the screen

the screen