Knowledge of routine light vehicle maintenance

If Liquid from a battery is spilled onto paintwork, it should be

• Blown off with an air line

• Wiped off with a dry cloth
• Washed off with water immediately

• Allowed to dry then polished off

Answer explanation

The liquid contains acid. Water will ‘weaken’ its strength and so reduce or prevent further damage

Which one of the following precautions should be taken when removing the pressure cap from the cooling system of a hot engine?

• The cap must be released slowly with a rag placed over it

• The engine must be running at a speed of less than 1000 rpm

• A dust mask must be worn to prevent the harmful vapours being inhaled

• A drain tray must be placed under the radiator and the cap removed quickly

Answer explanation

As the water is under pressure this will raise its boiling point. As the cap is removed, atmospheric pressure acts on the water and may cause it to boil.

The tool shown opposite is used to

• check tread depths

• balance road wheels

• measure tyre pressures

• remove balance weights.

Answer explanation

The tool shown is a tyre pressure gauge.

What is the minimum legal tread depth for a car tyre?

 

• 1mm

• 1.2mm

• 1.6mm

• 2mm

Answer explanation

The minimum legal tread depth is 1.6 mm for at least 75% of the tyre width and for the whole of its circumference.

Wheel nuts must not be over-tightened, otherwise the

• threads will become weaker

• tyre pressure will have to be increased

• wheel will be incorrectly locate

• assembly will become unbalanced

Answer explanation

Over-tightening will cause damage and over loading the threads. For this reason a torque wrench should be used to ensure they are tightened to the correct torque

During an inspection on a vehicle braking system, it is necessary to compare the thickness of the original front disc with a new one. Using the technical data sheet shown, a front disc has a thickness of

• 1.6mm

• 12.5mm

• 23.0mm

• 21.0mm

Answer explanation

The new front disc thickness is 23.0 mm.

A visual inspection procedure is used to check for

• scoring on a brake disc

• the thickness of a selective spacer

• the amount of bend on a drive shaft

• the clearance between a camshaft lobe and follower.

   

Answer explanation

A visual inspection would reveal a scored brake disc, all the other tests listed would require the use of measuring instruments.

The most suitable method of measuring the thickness of a brake disc is by using a

• dial test indicator

• vernier calliper

• internal micrometer

• calliper and rule.

Answer explanation

A vernier calliper is the most suitable, from those listed; the others are measuring instruments they would not be suitable for this task.

When fitting a replacement cartridge filter element to an engine lubrication system, it is important to

• use a sealant on the sealing ring

• put a sealant onto the mounting face

• tighten up the cartridge using a filter strap

• pour some engine oil into the element

Answer explanation

When starting the engine, if the new element was completely dry, it would allow the engine to run without oil for a short time, and this could cause damage to the bearing surfaces. Whenever possible, some new oil should be poured into the filter before fitting.

A record of work carried out will be found on a

• servicing schedule

• technical bulletin

• workshop manual

• job card

Answer explanation

All of these are documents that are used in automotive workshops, but the job card is used to record the work that has been carried out.