• What is a 12V battery?
• How will I know when to replace the battery?
• Why change the battery?
• How to change your battery, step-by-step
• How much does a new car battery cost?
• Where to buy a replacement car battery

What is a 12v car battery?

All cars have 12-volt batteries — petrol, diesel, hybrid and even pure-electric cars such as ones made by Tesla. They are used to run the 12v electrical system (lights, stereo, heating, etc.) and generally use lead-acid chemistry.

These batteries are designed to last for many years but they aren’t as energy dense as the lithium-ion batteries which are used to power an electric car’s drive motor and can be found in mobile phones and laptops. Nor do they like to be fully drained and then fully recharged, which is why they’re connected to an alternator (or dynamo in classic cars) that keeps them topped up while the car is running.

Draining your 12V battery completely — for example by leaving the interior light switched on —  is quite damaging to its long-term health. You can revive it via jump leads, but its efficiency will have been reduced. They also fade over time.

If you find your electrical system is having problems it may be down to a sluggish battery, and it will need replacing. Fortunately, this is an easy task and only requires basic tools. In most cases this procedure will take only half and hour or so.

How will I know when to replace the battery?

It’ll be obvious when your battery is completely flat — the central locking may not work and you won’t be able to start the engine — but knowing when a battery is reaching the end of its life is trickier. Many cars may have a battery warning light but if the battery fails while the car is parked, that’s not much help.

If you come to the car and find the battery is flat, you should still be able to start it up. Find the battery (usually under the bonnet, but check the car’s manual if you’re not sure) and use jump leads or a battery trickle-charger to send electrical charge from an external device directly into the 12V system (there should be instructions with the device).

You may also “bump start” a car with manual transmission. You do this by switching the ignition to “on”, depressing the clutch and engaging first gear, then have someone push the car forwards. Once you have sufficient motion, step off the clutch; this connects the moving wheels with the engine, turning it over and hopefully firing it up.

Once it’s started, take it for at least a 20-minute run to charge the 12v battery. When you get back, turn the engine off and restart it the next morning. If it’s flat again you’ll know there is a problem somewhere.

The first thing to do is check the battery leads are secure and clean.

Next, check the battery’s state of charge by either looking at the indicator eye (not present on all batteries), sampling the electrolyte in a battery hydrometer (not possible on sealed batteries) or perform a battery load or drain test with a suitable meter.

If it’s low, you should try replacing the battery with a new one.

Why change your battery?

Aside from the obvious inconvenience of being stranded somewhere without leads or someone to give you a bump start, a dead battery may require you to reset a car’s systems, such as the throttle position sensor, audio system, clock and more. This is undoubtedly time-consuming and Haynes strongly recommends fitting a new battery as soon as possible.

How to change your 12V battery

Work time

• Around 15-30 mins

Tools required

• Socket set – buy at Halfords.com

Parts that you may need

• New battery (£50-£200) – buy at Halfords.com
• Battery tray (£5-£15) – buy at Amazon.co.uk
• Battery retainer (£5-£10) – buy at Halfords.com

Note: A new battery retainer may not be required. It’s likely the original battery holder will still be useable. 

Changing a battery: step-by-step

Warnings: While a 12v battery will not shock you through the skin, there are safety considerations. Son’t do this in wet conditions and avoid connecting the two terminals with anything metal, as this will make a circuit and cause sparks/ heat. This means removing large metal jewellery. Wear insulated work gloves to be sure and consider safety goggles.

1. Undo the clamp nut and remove the cable from the negative terminal first.
2. Do the same on the positive terminal
3. Undo the battery hold-down clamp or bracket and lift out the battery. Be careful: it’s heavy
4. Examine the battery tray and clean it if necessary
5. Install the new battery, fitting the hold-down clamp(s) and securing the positive cable before the negative cable

How much does a new car battery cost?

The price of a car battery usually varies between £50 and £200 when purchased from online retailers. However, according to an investigation carried out by Auto Express some car owners may be charged up to a whopping £1,250 for a battery replacement by main dealerships. It’s really worth doing it yourself to avoid unnecessary cost.

Where to buy a car battery replacement

Several online retailers sell car battery replacements, including:

• Halfords – shop here
• Car Parts 4 Less – shop here
• Euro Car Parts – shop here
• Kwik Fit – shop here
• Amazon – shop here

Please note: all cars are different so if it is time to change your battery, you may want to look up instructions for your specific car at Haynes OnDemand. There may even be a video tutorial.

This article features products that have been chosen independently by Driving.co.uk journalists, and our reviews are unbiased. We may earn revenue if you click the links and buy the products, but we never allow this to affect our opinions.

• If you found our guide to changing a car battery helpful, you might also like our article on how to repair alloy wheel damage.
• Protect your car from theft with one of the best steering wheel locks on the market.
• We’ve also rounded up the best winter tyres to make driving in winter easier, safer and more enjoyable.

The post Haynes How-To: change a car battery appeared first on Driving.co.uk from The Sunday Times.

• What is an engine’s air filter?
• Why does the engine air filter need changing?
• How often should the filter be changed?
• How do you replace an engine’s air filter?

What is an engine’s air filter?

An engine’s air filter is rather a person’s lungs. Without the filter, your car can’t run properly and may incur serious damage.

It should not be confused with the filter that is used within the heating and ventilation system. As the name suggests, it is designed to filter all the air that is taken into heart of the engine, before it is mixed with fuel and ignited or compressed to power you along the road.

A good air filter will prevent dust and debris from entering the heart of the engine while providing good airflow for the air intake system. They can be made from either paper, foam or oiled cotton.

Why does the engine air filter need changing?

If the air filter is not fitted, or incorrectly installed, it can let debris into the precious areas of the engine and could cause costly damage.

Equally, if the filter becomes dirty over time – can you remember when it was last replaced? – it can hamper the airflow into the engine, restricting performance.

It should be noted that certain air filter manufacturers, which use oiled cotton components, say their part can be washed, returning it to as good as new condition.

How often should the filter be changed?

Vehicles manufacturers provide maintenance schedules for every model of car. This can vary, so read the vehicle’s service book, which will itemise the jobs that need doing over time. Typically, the engine’s air filter would be replaced every year. However, some long-life service schedules may see that extended to once every 18 months.

How do you replace an engine’s air filter?

Tools you will need (click to view at Halfords.com)

• Screwdriver or socket set

Parts you will need (click to view at Halfords.com)

• Air filter

Caution: Never drive the vehicle with the air cleaner filter element removed. Excessive engine wear could result, and backfiring could cause a fire under the bonnet
Below is an example video but look for a full step-by-step guide for your specific car at Haynes OnDemand, here.

A quick guide to changing an engine air filter

1. Make sure the engine is cold and that you have the correct tools for the job.
2. The air filter element is located in the air filter housing in the engine compartment. The vehicle handbook will show its location
3. Check there is no debris in the housing that could fall into the filter compartment as you lift the housing away. If there is, blow it out or use a vacuum cleaner to remove the debris
4. Undo any screws, blots or clips holding the air filter cover in place and carefully lift up the cover
5. If carrying out a routine service, the element should be renewed regardless of its apparent condition
6. If you are checking the element for any other reason, inspect its lower surface; if it is oily or very dirty, renew the element. If it is only moderately dusty, it can be re-used by blowing it clean from the upper to the lower surface with compressed air. Wear protective glasses when doing this. Remember, if it is a pleated-paper type filter, it cannot be washed or re-oiled. If it cannot be cleaned satisfactorily with compressed air, discard and renew it
7. Wipe out the inside of the housing. Check that no foreign matter is visible, either in the air inlet or in the air mass meter
8. Ensure the new air filter element is correctly fitted the right way up and then replace the housing and secure all screws and any clips

The post Haynes How-To: change an engine’s air filter appeared first on Driving.co.uk from The Sunday Times.

• Spare a thought for your car’s brake pads
• How brake pads work
• Why you should change your car’s brake pads
• When to replace brake pads
• Step-by-step guide to replacing a car’s front brake pads

Spare a thought for your car’s brake pads

Drivers rarely give much thought to their car’s braking system. Yet it is one of the most important safety features of any car.

Whether slowing in stop-start commuter traffic or using brakes to their maximum potential, when driving at a track day, who doesn’t take them for granted?

It’s only when the local garage mechanic advises that parts need replacing, or worse still, a red warning light illuminates on the dashboard, that we will stop and ponder the braking system. And that’s also when the cost of having parts replaced, such as the brake pads, comes into sharp focus.

However, changing brake pads is a relatively simple job that anyone with a modest ability for DIY should be able to safely accomplish. And if you already own most of the basic tools needed to perform the job, it will save you a few bob in garage costs and give a glowing sense of satisfaction, too. Here, the experts from Haynes explain how to do it.

How brake pads work

Brake pads are designed to work with a car’s brake discs, or rotors, to slow it down. They are installed in brake callipers and are pushed against the discs by pistons, which are in turn moved by brake fluid that is pressurised by a master cylinder.

When a driver pushes the brake pedal, the master cylinder compresses the fluid which in turn moves the pistons to ease the pads against the discs.

Some cars have brake pad wear indicators, which illuminate a light on the dashboard when the pads have worn down to a set limit. Most pads don’t, though, so the only way of telling how worn a pad is is to examine the level of fluid in the brake fluid reservoir (which drops as the pad wears) or to take the wheel off and inspect the material remaining on the pad.

Why you should change your car’s brake pads

Brake pads are critical components for the safe operation of your car, and should be maintained correctly to avoid a potential disaster. If the pads wear down completely you’ll not only damage the discs, which are expensive to replace, but may be unable to stop the car in time and cause a crash.

Each wheel has at least two pads and it’s important to change the pads on both front wheels at the same time, to ensure an even brake force across the pair of wheels.

At the same time you should examine the condition of the discs and look for signs of wear, or more serious scoring or corrosion, and have them replaced if needed.

When to change your brake pads

It’s important that your front brake pads are examined whenever the car is serviced and replaced when necessary. Modern cars typically require an annual inspection, or 18 months for longer service intervals.

If you hear unpleasant squealing when using the brakes, all may not be well with the pads. It is most likely caused by a small metal shim that is designed to make contact with the brake disc as the pad reaches the end of its serviceable life, warning the driver that it’s time to replace the pads.

Equally, if the car is pulling to one side of the road noticeably, when braking in a straight line on a flat, level road surface without camber, all may not be well with the brakes.

Brake pads may also have a sensor that activates a dashboard warning light when the pad has worn down, but not all models have these. So open the bonnet and inspect the level of the brake fluid in the reservoir. It drops as the pads wear, so can be a useful indicator of when pads need replacing.

Next, jack up the front of the car — see our guide on how to safely to this — remove the front wheels and examine the pads directly.

If there is less than 3mm of pad depth remaining, it’s time to change them.

All cars are slightly different, so you should consult the vehicle handbook, or use a Haynes manual for the relevant make and model.

Step-by-step guide to changing a car’s front brake pads

Tools you will need (click to view at Halfords.com)

• Brake system cleaner aerosol
• Wire brush
• Floor jack
• Screwdriver with flat head
• Allen key set
• C-clamp
• Socket set
• Torque wrench
• Ruler
• Pliers
• Gloves

You may also need

• Brake pads (Enter vehicle registration number to find correct part, or order from a franchised dealer)
• Copper grease

Below is an example video but look for a full step-by-step guide for your specific car at Haynes OnDemand, here.

A quick guide to changing a car’s front brake pads

1. Make sure the brakes are cold and that you have the correct tools for the job
2. Raise the car on a jack then support the car on jackstands
3. Remove the wheel
4. Clean the brakes using the degreaser and remove the caliper
5. Remove the pads from the caliper and examine the disc and brake line(s)
6. Insert the new pads and replace the caliper and any necessary clips
7. Check the brake fluid level
8. Refit the wheel
9. Jack up the car, remove the axle stands and lower
10. Use the torque wrench to tighten the wheel nuts

Haynes How-To: change engine oil and an oil filter

The post Haynes How-To: change front brake pads appeared first on Driving.co.uk from The Sunday Times.

• What are spark plugs?
• Why do spark plugs to be changed?
• How can you tell when your spark plugs need changing?
• How do you replace spark plugs?

What are spark plugs?

Spark plugs are used in petrol engines as a source of ignition. An electrical spark ignites the fuel, which forces the piston along the cylinder, which in turn causes the crankshaft to rotate. Without the spark plug the petrol engine wouldn’t be able to run.

Spark plugs are not used in diesel engines, which fire instead by simply compressing the fuel in the cylinders; no additional spark is necessary.

Why do spark plugs need to be changed?

Spark plugs need to be maintained properly if the engine is to operate smoothly. Neglect them and you could experience a number of problems.

For example, starting the engine may become a problem; you might have to turn it over several times before it fires, and this may flatten the battery over time.

In addition, once the engine is running it may have a rough sound when idling and could feel ‘lumpy’. The engine might even misfire (a distinct banging sound), which indicates that not all cylinders are working as they should. Misfiring should be sorted immediately, because you risk damage to the catalytic converter, which is expensive to replace.

A faulty spark plug may also increase fuel consumption and reduce engine power, and should be investigated at your earliest opportunity.

How can you tell when your spark plugs need changing?

Most modern spark plugs are made from ceramic and iridium or platinum, and should last for 60,000 miles or more. However they should be inspected every 30,000 miles or so, which will give you an idea of the health of the engine.

Consult your car’s manual, which should list the recommended intervals for changing your spark plugs. If you can’t find a recommendation, it’s worth removing them and checking their condition. It doesn’t take long and also gives you a clue as to how the engine is performing.
For example, a healthy spark plug will have light brown electrodes and insulator and no sign of melting, wear or deposits. However if you see oil deposits the piston rings may be worn. White deposits could mean that the plug isn’t of the right heat grade and carbon deposits show a rich mixture or weak ignition.

All cars are slightly different, so if it is time to change your thermostat, use our before you begin checklist, and find your car for specific instructions.

How do you replace spark plugs?

Changing a spark plug requires little experience, using basic tools, although you may need to remove other components to access the plugs. It will take up to an hour, depending on your model and could save you £75-£150 in garage fees.

Tools you will need (click to view at Halfords.com)

• Spark plug socket
• Torque wrench
• Ratchet
• Socket extension
• Spark plug gap gauge
• Spark plugs (£3-£25 each; see car’s manual for correct specification)

You may also need

• Anti-seize compound
• Spark plug wires/ HT leads (£20-£50; if the old ones are in poor condition)

Below is an example video but look for a full step-by-step guide for your specific car at Haynes OnDemand, here.

A quick guide to changing a spark plug

1. Make sure the engine is cold that you have the correct tools for the job. You may need to remove parts to gain access to the plugs
2. Work on one spark plug at a time. Remove the ‘boot’ from the top of the plugs with a twisting motion
3. Use a spark plug socket and ratchet to remove the plug
4. Adjust the new spark plug’s gap (if necessary), coat the threads with anti-seize compound and install the plug, being careful not to cross-thread it or over-tighten

The post Haynes How-To: change a spark plug appeared first on Driving.co.uk from The Sunday Times.

• Staying safe when changing a wheel
• Keep a high-visibility vest in your car
• Work on a stable surface
• Switch on the hazard warning lights
• Consult the vehicle handbook
• What you’ll need
• How to change a wheel, step-by-step

A PUNCTURE, pothole or unforgiving kerb can strike at any time. More often than not, however, it will be when it’s dark, raining and you’re nowhere near civilisation, which means you’re nowhere near a tyre fitter.

Drivers that don’t belong to a breakdown service, or lack any cover through their vehicle’s warranty, should know how to change a wheel. And that means checking that their vehicle has the correct equipment stored onboard at all times.

Here’s what drivers need to know to stay safe and successfully change a car’s wheel.

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Staying safe when changing a wheel

There are some strict dos and don’ts around changing a wheel and tyre. That’s because you will be exposed to traffic in close proximity and are at risk of being struck by another vehicle. Equally, your car could slip from its jack, meaning a risk of injury.

The most important rule is to not attempt to change a wheel on a motorway or at the side of a busy road. Either use the emergency phones or your mobile to call for assistance, which will see you moved to a safer location, or move the vehicle well away from the road and passing traffic, such as to a driveway or layby.

Keep a high-visibility vest in your car

The moment your car breaks down is the moment you need to make sure you’re visible to other drivers. Walking or working around a car, especially at night, leaves you vulnerable to being struck by another vehicle. So keep a high-visibility vest in your car’s glovebox and put it on before exiting the vehicle. They cost from less than £2 and could save your life.

Work on a stable surface

Ensure the vehicle is stopped over a level surface that is stable. A solid stretch of asphalt, such as a car park or driveway, is ideal.

Switch on the hazard warning lights

You’ll need to let other road users know that your vehicle is stranded and presents a hazard, so turn on the car’s hazard warning lights and also consider keeping the side lights on if ambient light levels are low.

Consult the vehicle handbook

This will tell you where the tools are stored onboard your car, and details the location of the jacking points beneath the vehicle.

What you’ll need

• High-visibility vest
• Torch (for night)
• Reflective warning triangle
• Gloves or wet wipes (to keep your hands clean)
• Chocks for the wheels
• Jack
• Wheel wrench/brace
• Spare wheel or space-saver wheel

How to change a wheel, step-by-step

1. The spare wheel and tools are usually stored in the car’s luggage compartment. However, on some vehicles the spare wheel is underneath the car
2. Remove the tools and any reflective warning triangle
3. Place the reflective warning triangle further along the road, if you are unable to park the vehicle off the road
4. Remove the spare wheel by slackening any retaining nut and plate, and lift it from the luggage compartment
5. Place a wheel chock behind or in front of the wheel diagonally opposite to the one to be removed
6. Remove the existing wheel’s trim or hub cap (if applicable) then use the wheel wrench to slacken each wheel bolt by a half turn. You will remove them only once the car is raised on the jack
7. If anti-theft wheel bolts are fitted, they can be slackened using the adapter supplied in the tool kit
8. Place the head of the jack under the jacking point nearest to the wheel that is to be removed (as identified in the vehicle handbook), ensuring it is on stable ground
9. Begin to raise the jack, turning the handle clockwise. The head must enter the recess in the jacking point
10. Continue to raise until the wheel is clear of the ground
11. Unscrew the wheel bolts and remove the wheel
12. Fit the spare wheel and screw in the bolts. Lightly tighten the bolts with the wheelbrace then lower the vehicle to the ground, by turning the jack handle anti-clockwise
13. Securely tighten the wheel bolts in the sequence shown then refit any wheel trim/hub cap
14. Remove the wheel chock on the opposite side of the car
15. Stow the punctured wheel and tools back in the luggage compartment and secure them in position using the retaining nut and plate
16. Note that the wheel bolts should be slackened and retightened to 100 Nm (74 Ibf ft) at the earliest possible opportunity

For more Haynes guides, go to driving.co.uk/car-clinic/haynes-how-to/

The post Haynes How-To: change a car wheel appeared first on Driving.co.uk from The Sunday Times.

• How to safely jack up a car
• What you’ll need
• How much do trolley jacks and axle stands cost?
• Jacking up a car, step-by-step

How to safely jack up a car

Hundreds of thousands of Britain’s drivers like to carry out maintenance on their car. From changing spark plugs to draining engine oil, fitting new brake pads to replacing engine coolant, there are plenty of tasks that can be accomplished by drivers with little mechanical knowledge. It’s satisfying, gives you something to boast about to friends and can save a small fortune compared with having the work done at a garage.

To achieve many of these tasks, a car needs to be raised from the ground, giving space to work around the engine or other components. And that calls for a jack.

There are some simple but essential rules that anyone raising a car on a jack should follow. Failing to do so could mean that a harmless spot of DIY turns into an emergency visit to the local hospital, or worse. There is a serious risk of being crushed by the vehicle if the correct precautions aren’t followed.

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The most important rule is to not let children near the vehicle, or leave it unattended. And keep a phone to hand, in case of an emergency.

Only raise a vehicle using a jack when it is parked on a flat, stable surface. Ideally, that would be a garage floor or a paved driveway, and it must be out of harm’s way from moving traffic.

Before jacking the vehicle, always place chocks behind the wheels at the opposite end of the car to help prevent it from moving. Ensure the handbrake is applied, put the car in first gear or, if it has an automatic gearbox, put it in ‘Park’.

If you need to remove any of the wheels for your DIY task, slightly loosen the wheel nuts before raising the vehicle (you’ll unscrew them completely when the car is off the ground).

What you’ll need

As any mechanic will advise, the type of jack that is safest to use is known as a trolley jack. It is more robust and able to lift heavier loads than the simple scissor jack supplied with the vehicle. The latter is designed for emergency use at the roadside, when a car’s tyre suffers a puncture.

Next, anyone wanting to roll up their sleeves and get under their car will need to secure it using axle stands. The car should not be supported by the jack – only raised, so that the axle stands can be positioned under the car before it is lowered onto them. Again, these should be capable of supporting more than the car’s weight.

How much do trolley jacks and axle stands cost?

Trolley jacks cost from £25, but can be more than £100 for top-end models. You should check the weight of your vehicle, in the user manual (handbook) and buy a jack that is capable of lifting more than the car’s weight. Axle stands cost between £15 and £70, depending on the brand and weight they will support.

Jacking up a car: step-by-step

Read the vehicle handbook. If needed, refer to the full haynes.com/ondemand service – there may even be a video tutorial.

1. Ensure the vehicle is on a flat, stable surface
2. Apply the handbrake, put the car in first gear or ‘Park if it is an automatic gearbox
3. Chock the wheels at the opposite end of the vehicle to the one you are jacking, to prevent movement of the car
4. If you intend removing a wheel, always loosen the wheel nuts before you jack the car
5. Always use a hydraulic trolley jack, never use your emergency jack supplied with the car
6. Using the jacking locations as specified in your car’s handbook, carefully raise the car using the trolley jack. These designated points are robust enough to prevent any damage being caused to the car, whereas placing the jack beneath the engine’s oil sump, floor pan or suspension components could cause an expensive breakage
7. Position the axle stands placed at the specified jacking points. The vehicle handbook will show the locations
8. Carefully lower the vehicle onto the jacking stands
9. Some people like to leave the jack in position as well, so it can work as a fail-safe should there be any problem with the axle stands. However, this will depend on whether or not it obstructs the area where you need to work
10. Once you have finished the maintenance task, use the jack to raise the vehicle from the axle stands, remove the stands and then carefully lower the vehicle to the ground
11. If you removed a wheel and replaced it, remember that the wheel nuts will need tightening

The post Haynes How-To: jack up a car appeared first on Driving.co.uk from The Sunday Times.

• How an engine’s cooling system works
• Why you should change your coolant
• When to change your coolant
• Working safely with coolant or antifreeze
• How much does new engine coolant cost?
• How to change engine coolant, step-by-step

How an engine’s cooling system works

Coolant is an engine’s lifeblood, keeping it at the correct operating temperature, helping it to warm up quickly in cold weather and not get too hot when under stress. And when the temperature plummets to below freezing, if mixed with the correct antifreeze, coolant prevents damage. It performs another important role, too, as it stops corrosion taking place within certain engine parts.

The way coolant works within the engine’s cooling system hasn’t changed much over the past 100 years. The cooling system circulates the coolant fluid around specially designed cavities within the engine block to keep the temperature at its optimum operating point, before being passed through a large radiator, which air passes through, cooling the fluid within the system.

Take a look at your car’s handbook for coolant change intervals, or speak with a service department at a franchised garage, as they will be able to advise on the car maker’s recommended intervals for replacement. Some models need a change every couple of years but others can go for longer.

Why you should change your coolant

Over time, the effectiveness of the coolant fluid in a car’s cooling system deteriorates. For that reason, periodically, the cooling system should be drained, flushed and refilled to replenish the antifreeze mixture and prevent formation of rust and corrosion, which can impair the performance of the cooling system and cause engine damage.

The antifreeze chemicals in the coolant lose their effectiveness, especially if you top up the coolant with water regularly. In harsh winter weather this can lead to the coolant freezing and expanding, which can damage components.

When to change your coolant

Always consult your vehicle’s handbook for recommended intervals, but mechanics often suggest that every two years is a suitable period. If you can’t remember the last time the coolant was changed, and it’s looking cloudy and discoloured, change it now.

Part of a car’s cooling system service involves flushing. If the coolant is changed on a regular basis you may need to flush only once before refilling.

Working safely with coolant or antifreeze

Always wait until the coolant is cold before draining it. Don’t allow antifreeze to come in contact with your skin or eyes or painted surfaces of the vehicle. Rinse off spills immediately with water. Never leave antifreeze lying around in an open container or in puddles on the floor; children and pets are attracted by its sweet smell and may drink it.

Check with local authorities about disposing of used antifreeze. Many communities have recycling sites which will see that antifreeze is disposed of safely. Never dispose of used antifreeze on the ground or pour it into drains.

How much does new engine coolant cost?

Check the vehicle handbook, or with the manufacturer, for the quantity and any recommendation of antifreeze brand. Some car makers suggest only using certain brands, due to aluminium components used within the cooling system. Antifreeze can be bought as a neat solution, which should then be mixed with water according to the vehicle maker’s recommendation, or you can buy it ready-diluted. Prices vary, from around £2.50 for a litre of neat antifreeze, to up to £30 for a car maker’s branded, five litre ready-mixed solution.

How to change engine coolant

Work time

• Up to two hours

Parts and tools that you may need

• Gloves and protective eyewear
• Pan or bucket to collect water
• Floor jack (if necessary)
• Axle stands
• Ratchet and socket set
• Screwdriver
• Rags
• Pliers
• New coolant
• Replacement hoses (if found to be faulty)

Changing engine coolant: step-by-step

Read the vehicle handbook. If needed, refer to the full haynes.com/ondemand service. (There may even be a video tutorial) to see if further dismantling is required

1. Make sure the engine is cold, handbrake applied and vehicle is in first gear
2. Raise the front of the vehicle on a jack
3. Place jackstands beneath the car and lower it into position, ensuring the back wheels have chocks in place
4. You may need to remove any underbody shield
5. Place a container under the radiator and undo the drain valve (see vehicle handbook for location)
6. Flush the system as many times as necessary
7. Locate and remove the reserve tank from its holder and drain any coolant remaining, then put the tank back in place
8. Replace the drain valve
9. Refill the system to the base of the filler neck, with the correct antifreeze
10. Follow Haynes’ instructions for bleeding/topping up procedures: you may need to run the engine briefly, then top-up the coolant, replace the radiator cap, then run the engine again until the cooling fan turns on, before checking levels and topping up as required.

The post Haynes How-to: check and change engine coolant appeared first on Driving.co.uk from The Sunday Times.

• How headlights work
• When to replace a bulb?
• Do headlight bulbs deteriorate over time?
• Cost of new headlight bulbs and which does my car need?
• How to change a headlight bulb, step-by-step

How headlights work

All cars have sidelights and headlights. Older and cheaper cars tend to use halogen bulbs which are straightforward to replace.

This task requires no experience and few, if any, tools, and will take a matter of minutes to complete.

Newer, or more expensive models feature bulbs filled with xenon gas, which gives a brighter, whiter light. These are often called Xenon lights, and are also known as high intensity discharge (HID) lights.

However, it’s important drivers treat such systems with caution: high voltages produced by HID systems can be fatal in the event of a shock. And the voltage can remain in the circuit even after the headlight switch has been turned off and the ignition key has been removed. Therefore, for safety, we don’t recommend that you try to remove one these headlight housings.

Instead, have this service performed by a dealer service department or other independent garage. Alternatively, Halfords offers a bulb-fitting service for £8.

When to change a car’s headlight bulbs

The obvious time to change a headlight bulb is when it stops working. Without a full set of functioning headlight bulbs you’re making night-time driving more difficult for yourself and aren’t making yourself as visible to other road users and pedestrians.

You also risk being pulled over by the police. Assuming this is the first time you are stopped for the fault, you will be handed a ‘vehicle defect rectification notice’ which gives drivers 14 days to prove to police that they have had the required repair made, such as by presenting the vehicle or a receipt for work carried out.

Do headlight bulbs deteriorate over time?

Over time and after prolonged use, the lighting performance of a halogen bulb will reduce. This is because the filament deteriorates gradually. So if a car’s headlamps haven’t been replaced for a number of years, it can be a good investment to change them. At the same time, the technology behind bulbs has led to improvements in lighting performance, so it’s possible that drivers could benefit from an improvement in light of 100 per cent or more.

The cost of replacement bulbs and which does my car need?

Bulbs can cost from a few pence to more than £100. It’s important to be aware there aren’t only different manufacturers of bulbs and lights with varying wattage, but very particular fittings that dictate compatibility with a car.

There are several simple ways to check which bulbs fit your car. Some cars’ handbooks will give details of the type of bulb needed, and the process of changing a bulb. Alternatively, call a franchised dealer and speak with a service advisor, or visit an online retailer, such as Halfords, Autobulbdirect or Eurocarparts. These allow you to enter the registration of the vehicle, or select the make, model and year, and match a range of compatible bulbs to your car.

How to change headlight or indicator bulb

Work time

• Around 5 mins

Parts that you may need

• Replacement bulb

Changing a bulb: step-by-step

Read the vehicle handbook

If needed, refer to the full haynes.com/ondemand service. (There may even be a video tutorial) to see if further dismantling is required

1. Open the hood and locate the back of the headlight housing
2. Remove any cover and locate the blown bulb. You may need to twist out the connector, or release spring levers and disconnect the electrical connectors
3. Remove the bulb. Install the new bulb – being careful not touch it with your skin. The oil left from your skin will heat up on a lit bulb and cause damage to the glass.
4. Check the new bulb is securely connected then return in the headlamp unit, fasten it securely and replace any cover
5. Check that the bulb works correctly

The post Haynes How-To: change a headlight bulb appeared first on Driving.co.uk from The Sunday Times.

• Why replace a wiper blade?
• How will I know when to replace a wiper blade?
• Cost of new wiper blades and which does my car need?
• Tips for caring for wiper blades
• How to change a wiper blade, step-by-step

Why replace a wiper blade?

It goes without saying that drivers need to be able to clearly see the road ahead to remain safe on the road. For a car to be in roadworthy condition, and pass its annual MOT test (if more than three-years old) it must have windscreen wipers, which should be correctly secured and in good working condition.

Given that the UK and rain go together like the Queen and Buckingham Palace, Britain’s drivers rely on their cars’ windscreen wipers. On average, the UK has 131 days a year with rainfall of 1mm or more. However, in parts of Wales, that rises to 160 days, and in Scotland it can be as high as 220 days a year.

Over time and use, the effectiveness of wiper blades deteriorates. This can lead to a smearing effect of water, which obscures the view through the windscreen. That can cause a car to fail its MOT.

Even if drivers don’t live in a rainy climate, a car’s wiper blades should be replaced roughly every 12 months because the rubber gradually perishes when it’s exposed to sunlight or cold temperatures and its wiping performance worsens.

New wipers are easy to fit, relatively affordable and ensure good visibility in bad weather, so they’re a wise investment.

This task requires no experience and only basic tools, and can be completed in a matter of minutes.

How will I know when to replace wiper blades?

The first and most obvious sign that windscreen wipers need replacing is when they begin to smear or leave streaks of water across the glass. Other telltales signs during operation include a juddering effect as they pass over the glass, or unusual noises — as they should be silent.

Every month, give the wiper blades a clean (see below) and then run your fingertips along the edge of the rubber blade, feeling for any tears or cuts. It’s important to remember to check the operation and condition of the rear wiper blade too.

Cost of new wiper blades and which does my car need?

Wiper blades can be bought from most car care stores, garages or ordered online. It’s often cheaper to buy them online, using sites such as halfords.com, wiperblades.co.uk or eurocarparts.com. Prices start from roughly £5 for a single wiper, and £14 for a pair.

These sites make it easy to choose the correct fitment wipers for their car, by using a vehicle registration search tool. However, before buying the wipers, take a moment to go to your car and remove an existing wiper blade.

This should be simple to do – see basic guide below – but as all cars are different, you can also check the vehicle handbook or look up instructions for your specific car at haynes.com/ondemand. There may even be a video tutorial.

Tips for caring for wiper blades

Some drivers reports that even brand new wiper blades can leave smears, or judder across glass. A suggested cure for this, from wiperblades.co.uk, is to wipe the rubber blade with paper towel or cloth damped using malt vinegar, or neat windscreen washer fluid.

Over time, it’s a good idea to clean your wiper blades when washing your car. Lift them proud of the windscreen, then wash the rubber blades with a wet sponge or microfibre mitt or towel. This will remove the dirt that accumulates around the base of the rubber blade.

Alternatively, at a petrol station take some paper towels and wet them, before wiping them along the rubber blade. This is also an ideal location to top-up the windscreen washer fluid, taking care to use the appropriate dilution of washer fluid and water according to the manufacturer’s instructions.

When returning to the car after rain has stopped, before starting the car make sure the wipers are switched off, or else they will drag across the dry windscreen, which is abrasive to the rubber. In freezing conditions make sure the wipers aren’t stuck to the windshield or rear screen before use, as this could tear the rubber blade or cause damage to the wiper motor unit.

How to change a windscreen wiper blade

Work time

• Around 5 mins

Tools required (optional)

• Flat-head screwdriver

Parts that you may need

• Replacement wiper blades

Changing a wiper blade: step-by-step

1. For wiper arms with a retaining clip: lift the arm from the glass, swing the blade so it is at a right angle to the arm and press the central lever within the fastening mechanism to release the wiper blade from the arm. In some instances, a screwdriver may help to release the fastening clip.
2. For wiper arms without a retaining clip: lift the arm from the glass, swing the blade so it is at a right angle to the arm and simply pull the blade free from the arm.
3. Replace with the new wiper blade, and check they are fastened securely.

Please note: all cars are different so if it is time to change your wiper blade, you may want to look up instructions for your specific car at haynes.com/ondemand. There may even be a video tutorial.

The post Haynes How-To: change a wiper blade appeared first on Driving.co.uk from The Sunday Times.

• What is engine oil for?
• Which oil does my car need?
• How often does engine oil need changing?
• When should an engine oil filter be changed?
• Disposing of old engine oil
• Step-by-step guide to changing engine oil and the oil filter

What is engine oil for?

An engine is made up of highly stressed, precious components, many of which are thrashing around at great speed. To lubricate and protect the moving parts, manage friction and the build up of heat and keep those precious components clean, engine oil is required.

Because of the differences in design, materials used and the variation in the speed at which components are moving, different engines will often require different grade of engine oil. This is also known as its viscocity, and is essentially a measure of how runny the oil is when cold and when hot. All oils are developed to meet certain viscocity measurements, and car makers will recommend a certain grade of oil to be used with a specific engine.

Which oil does my car need?

Finding out which engine oil a car’s engine needs is simple. Consult the vehicle handbook, or if it’s not available, speak with a reputable garage or the vehicle manufacturer’s customer service department.

How often does engine oil need changing?

As oil ages, its ability to protect an engine deteriorates. At the same time, the oil filter, which is used to capture minute particles of dirt and debris and protect the engine from damage, becomes clogged.

Vehicle manufacturers have recommended service intervals for their models, that specify which tasks should be carried out and when, including changing the engine oil and the oil filter. These can vary, between once every six months or 3,000 miles, up to once every 24 months or around 20,000 miles. To establish the correct intervals for your car, check the vehicle handbook or speak with the car manufacturer’s dealers or customer service department.

When should an engine oil filter be changed?

The oil filter should be changed each time the engine oil is replaced.

Disposing of old engine oil

Oil must be disposed of safely using specialist facilities. Councils’ local recyling centres will have a dedicated container for collecting engine oil.

How to change engine oil and an oil filter

Work time

• Less than one hour

Tools required

• Protective gloves
• Socket set
• Car jack
• Axle stands
• Funnel and container or drip tray for oil collection

Parts that you may need

• Oil
• Sump plug
• Oil filter

Changing engine oil: step-by-step guide

1. To help drain as much oil as possible, start the car to warm the engine before you begin work. You don’t want to get it up to full working temperature as the oil, and engine, will become too hot, but just until the temperature gauge starts to move.

2. Put on protective gloves, open the bonnet, and remove the oil filler cap – this will help the oil drain more quickly. Then, on firm, level ground raise the car using a jack and secure it on axle stands. You will need to work underneath the car, so it’s vital that it is secure and safe. Chocks placed either side of the back tyres can help prevent it moving.

3. Many cars have a large plastic undertray. You may need to remove this to access the sump plug, although some cars have a ‘flap’ or smaller removable section. Check the vehicle handbook, or online if unsure.

4. Locate the oil sump plug, using the vehicle handbook to help identify the correct part. Place a suitably sized drain container underneath the sump plug. Undo the sump plug with a suitable sized spanner or ratchet. It might be quite tight. Be ready to move the container to catch the oil, and ensure the plug doesn’t fall into the oil container, and that you don’t lose the copper washer.

5. Locate the oil filter, which will be either a cannister type or a filter housing with a removable lid. Sometimes they’re accessible from underneath the car, and on some cars access may be from above the engine. Again, the vehicle handbook can help identify its location. Unscrew either the canister, or remove the lid of the filter housing. Oil will also come out of the filter, so be prepared to catch any waste.

6. When all oil is drained from the engine, replace the sump plug. It’s advisable to use a new item complete with a new copper washer.

7. Next, refit the oil filter. If it’s the canister type clean the area where it mates to the engine and smear some oil around the black rubber seal. Tighten firmly by hand; DO NOT over-tighten. If it’s the element type, refit the new element and secure the housing lid. It’s likely to be a plastic housing so again, don’t over-tighten.

8. Don’t refit the undertray (if fitted) just yet. Before refilling the engine with the new oil, it is essential to check the oil capacity of the car’s engine – adding too much oil can cause catastrophic engine failure.Use a funnel to prevent spills, and always add oil gradually, checking the dipstick (or any digital readout) as you go. Once certain that the oil is at the ‘full’ level marked on the dipstick, replace the oil filler cap on the top of the engine.

9. Start the engine, but do not rev it up. It needs to build oil pressure, which is why the oil pressure light will stay on for longer than usual. It should extinguish within a few seconds. Leave the engine running and check the filter and drain plug for leaks.

10. If all is well, refit the undertray. Allow the engine to cool a little, and the oil to settle, and use the dipstick to check the level again.

How to remove a stuck oil filter

Sometimes the screw-on canister-style oil filter won’t budge. In such an instance, pull on a pair of rubber gloves (for grip) summon up all your strength and give it a good turn, anti-clockwise.

If it won’t unfasten you’ve got a couple of options. The sensible approach is to get an oil filter wrench. These are generally rubber or metal and grip the canister sides, giving extra leverage without damaging the housing.

Alternatively, if the shops are shut and the job needs to be completed, you could consider driving a long screwdriver through the side of the canister, and use that to hopefully add leverage. However, oil will spill and there’s a chance the metal canister will rip, meaning you’ll need the specialist filter wrench.

The post Haynes How-To: change engine oil and an oil filter appeared first on Driving.co.uk from The Sunday Times.