Fluid level checks Haynes Shows You How

In simple terms you should never exceed the manufacturer’s recommended service intervals. Over time oil and coolant can degrade and their performance and ability reduce.

Not adhering to service intervals can decrease the reliability and life expectancy of your engine, so it's simply unwise to seek out a way to extend the life of your fluids. 

How long should your car’s fluids last?

With the advent of modern oils and additives, engine oil and coolant lasts longer than it ever has – but that doesn't mean you should ignore the service intervals.

It's generally recommended that you change your oil at least annually, or every 16,000km, whichever comes first. Although some manufacturers state shorter, or longer intervals between changes.

Coolant generally has a much longer service life, with some manufacturers recommending a 15-year, or 240,000km change! But a shorter, five-year or 80,000km interval is a more common recommendation.

With both of these fluids it's important that you consult your handbook, or ask your dealer to find out the correct intervals.

How much does it cost to change your engine oil and filter?

Depending on your car, and how much oil it uses, the price will vary but for an average car (such as a Ford Focus) an oil filter (which you must always change at the same time as carrying out an oil change) can cost you less than $20 and the oil will cost between approx $30 and $120 depending on how posh the oil of your choice is.

The same job at a dealer is likely to cost you up to $250 depending on their hourly rate, so you can see that there is a considerable saving to be made. 

Why you should check your fluid levels

Most of the fluids in your engine bay are critical for the car’s operation. Among the most important are the engine oil and coolant, which is why these should be checked weekly. A low engine oil level will cause the engine to wear more quickly, and if it drops to a dangerous level the engine could seize. It’s a similar story with the coolant.

Brake, clutch and power steering fluid are still important fluids but don’t need to be checked as often. However, a drop in level from month to month indicates a leak in the system, and it’s important to fix this as soon as possible, rather than to keep topping up the fluid.

“Always make sure you use the correct fluids when topping up”

Weekly fluid checks include: engine oil, engine coolant and windscreen washer fluid (if possible).

Monthly fluid checks include: battery electrolyte (if the battery isn’t sealed), brake and clutch fluid.

Before carrying out any fluid checks make sure the car is parked on level ground. You’ll find it easier to do these checks in good daylight. Use your car’s handbook, which will show you where the fluid reservoirs are located. Always make sure you use the correct fluids when topping up - never mix different grades of engine oil and brake fluid. If in doubt take a look at previous service receipts for details, speak to the shop that carried out the last service or consult your car’s handbook.

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

Your engine oil is the fluid you'll want to keep the closest eye on. Modern engines place great demands on their oil, so it is very important that the correct oil for your car is used.

If you have to add oil frequently, you should check whether you have any oil leaks. Place some clean paper under the car overnight, and check for stains in the morning. If there are no leaks, then the engine may be burning oil, or the oil may only be leaking when the engine is running.  

Always maintain the level between the upper and lower dipstick marks. If the level is too low, severe engine damage may occur. Oil seal failure may result if the engine is overfilled by adding too much oil. 

Before you start

• Make sure that the car is on level ground. 
• The oil level must be checked with the engine at normal operating temperature, however, wait at least 5 minutes after the engine has been switched off. 

Checking your engine oil is at the right level 

1. The dipstick is brightly coloured for easy identification. Withdraw the dipstick.
2. Using a clean rag or paper towel remove all oil from the dipstick. Insert the clean dipstick into the tube as far as it will go, then withdraw it again.
3. Note the level on the end of the dipstick, which should be between the upper (MAX) mark and lower (MIN) mark. Approximately 1.0 litre of oil will raise the level from the lower mark to the upper mark.
4. Oil is added through the filler cap. Unscrew the cap and top-up the level. A funnel may help to reduce spillage. Add the oil slowly, checking the level on the dipstick frequently. Avoid overfilling.

Warning: do not attempt to remove the expansion tank pressure cap when the engine is hot, as there is a very great risk of scalding. Do not leave open containers of coolant about, as it is poisonous.  

With a sealed-type cooling system, adding coolant should not be necessary on a regular basis. If frequent topping-up is required, it is likely there is a leak. Check the radiator, all hoses and joint faces for signs of staining or wetness, and rectify as necessary.  

It is important that antifreeze is used in the cooling system all year round, not just during the winter months. Don’t top-up with water alone, as the antifreeze will become diluted.  

The coolant level varies with the temperature of the engine, and is visible through the expansion tank. When the engine is cold, the coolant level should be between the MAX and MIN marks on the front of the reservoir. When the engine is hot, the level may rise slightly above the MAX mark.

If topping-up is necessary, wait until the engine is cold. Slowly unscrew the expansion tank cap, to release any pressure present in the cooling system, and remove it.

Add a mixture of water and antifreeze to the expansion tank until the coolant level is halfway between the level marks. Use only the specified antifreeze – if using Ford antifreeze, make sure it is the same type and colour as that already in the system. Refit the cap and tighten it securely.

All manual transmission models have a hydraulically operated clutch, which uses the same fluid as the braking system. 

Warning: hydraulic fluid can harm your eyes and damage painted surfaces, so use extreme caution when handling and pouring it.