What’s under the bonnet of your car? Preparing for your driving test questions

Published on 18 January 2021

The driving test is the last step of getting a driving license. However, you’ll need to know more than just the traffic rules and how to drive safely; you'll also need to know what’s under the bonnet of your car.

These questions are to make sure that you're able to perform a series of basic car safety checks before getting behind the wheel, and that you’ll be able to solve a problem that may present itself every now and again when you’re on the road. However: although the examiner may ask you to actually open and close the bonnet, they won’t ask you to actually check the fluid levels – instead, they will simply have you explain how you would do it.

How are fluid levels checked?

  • Engine oil

    The examiner may ask you where your engine oil is located and how you would check the oil level. In this case, you should indicate where the dipstick and the cap for the engine oil tank are located. The dipstick often has a bright colour, usually yellow, with some type of handle on the visible end to help you grab it.

    To check the engine oil level, the first step is to remove the dipstick and clean it. Then you should reinsert it and take it back out again to check where the oil mark is, which should always be somewhere between the minimum and maximum lines. You should also mention that to accurately measure the level of the different fluids, the car must be parked on a level surface.
  • Coolant

    The coolant reservoir is easily identifiable because the coolant typically has a bold, striking colour – either orange, yellow, green, blue or pink. It comes with a screw cap because it must properly pressurise the system and when the liquid reaches a high temperature, it also sets off a warning light. 

    To check the coolant level, simply look at one side of the tank. The coolant should be in between the minimum and maximum marks or reach the line if there is only one mark. During your test, you can also mention that before unscrewing the cap, you must first wait for the engine to cool down to avoid burning yourself. If you don’t have any coolant on hand, you can add distilled water, but never tap water.
  • Brake fluid

    You will be able to identify the brake fluid reservoir because the cap has a warning indicator, as well as a symbol associated with the brakes. Brake fluid is usually yellow. The brake fluid level is easily checked; you just need to make sure that it’s between the minimum and maximum lines.

    You can also mention that, in addition to the brake fluid level, it’s important to check its colour. It should be slightly translucent and yellowish, because when it acquires a brown hue, it needs to be changed.
  • Windscreen washer fluid

    The cap on the windscreen washer reservoir usually has an icon depicting a jet of liquid, so it’s not difficult to identify. There are no external markings that indicate the minimum and maximum levels, so you will simply need to explain that you would remove the lid to visually check the level.

    Also, you should specify that it’s important to check the windscreen washer fluid level regularly, especially before taking a long road trip. 

Another important component in the car that the examiner might ask you to identify is the battery, as it powers the car’s electrical systems. If the battery runs out, you’ll need to charge it with either a charger or use jump leads with the help of another vehicle. The examiner may also ask you to identify the fuse box. Although some cars may have more than one, the main one is usually close to the engine and contains the starter and injection system fuses. You can remove the lid without the need for any tools and it can be identified with a fuse icon.

How to correctly open and close the bonnet

Opening the bonnet properly will get you off to a good start in this part of the driving test. The bonnet is opened differently in each vehicle, although in many car models, the handle is located on the left side of the driver’s seat. Simply pull it up towards you until the bonnet opens slightly.

On the bonnet itself, each vehicle has its own opening system, but it’s usually a tab in the centre that you must push up. You can open it with the hand opposite to the one you’ll use to place the prop rod. Make sure to properly position the prop rod to support the hood. 

Once you’ve located all of the car’s elements, the examiner will ask you to close the bonnet to begin the driving part of the test. To close it properly, release the prop rod with one hand, while supporting the bonnet with the other. Put the prop rod back into place and let the hood drop down to about a foot above the car body, and then drop it to latch it securely; don’t let it drop directly from above.